Algebraic Expressions Answer Key

MATHEMATICS ALGEBRAIC EXPRESSIONS 1. Simplify: 81a²b²c² + 64a⁶b² 144a⁴b²c 2 2 2 2 (A) a b [9c  8a ] 2 2 2 2 (B)  a b [9c  8a ] 2 2 2 2 (C) a b [9c  8a ] (D) None ANS . C 2. Simplify: (a²+b² + 2ab) + (a² + b² - 2ab) (A) – 2a2 + 2b2 (B) 2a2 – 2b2 (C) 2a2 + 2b2 (D) (2a2 – 2b2) ANS . C 3. Simplify: 2x – [3y – {2x – (y – x)}] (A) 5x + 4y (B) 5x – 4y (C) – 5x – 4y (D) – 5x + 4y ANS . B 4.  m  [m  {m  n  2m  (m  2)}  n ]  (A) 2n (C) – 2n ANS . C (B) 3n (D) – 3n Simplify : 85  [12x  7(8x  3)  2{10x  5 (2  4x )}] (A) 44  104x (B)  44  104x (C) 44  104x (D)  44  104x ANS . A 5. 6. Subtract 2x³ + x² - 4x – 1 from 5x³ + 5x² + 9 3 2 3 2 (A)  3x  4x  4x  10 (B) 3x  4x  4x  10 3 2 (C) 3x  4x  4x  10 ANS. B 3 2 (D)  (3x  4x  4x  10) 7. a4 + 4a2b2 + b4 is more than a4 – 8a2b2 + b4 by (A) 12a2b2 (B) – 12a2b2 (C) 2a4 + 2b4 (D) None ANS . A 8. The value of (x + 2y + 2z)² + (x – 2y – 2z)² is (A) 2x² + 8y² + 8z² 2 2 2 (B) 2x  8y  8z  8xyz 2 2 2 (C) 2x  8y  8z  8yz ANS . D 2 2 2 (D) 2x  8y  8z  16 yz Simplify : xy  [ yz  zx  {yx  (3y  xz )  ( xy  zy)}] (A) xy  2zx  3y (B) xy  2zx  3y (C) 3xy  2zx  3y (D) xy + 2zx – 3y ANS . D 9. Simplify :  3 (a  b)  2 (2a  b)  4a  5 (A) 5 (a – b + 1) (B) 5 (a + b + 1) (C) 5 (a + b – 1) (D) 5 (a – b – 1) ANS . D 10. 11. If a = – 2, b = 3 and c = 4, then the value of a³ + b³ + 3a²c – 4bc³ is (A) 107 (B) – 107 (C) 701 (D) – 701 ANS . D 12. P = a³ - 4b³ + 3a² b, Q = -4a³ + 13a² b + 7b³, R = - 4a² b + 8b³ + 3a³ and S = 12a² b-5b³+ 9a³ and P – Q + R – S is equal to - (A)  a  3b  26 a b 3 3 2 (B) a  2b  26a b 3 3 2 (C) a  2b  26a b 3 3 2 (D)  a  2b  26a b ANS . A 13. Simplify : 3 3 2 7 – [3x + {– 2y + 3z – (3y + 5z) + 8} – (3y2 + 7x) + 9] (A) – 1 + 4x – 3y – 3z + 3y2 (B) – 10 + 4x + 5y + 2z + 3y2 (C) – 10 – 4x + 5y – 2z + 3y2 (D) – 1 + 14x – 5y + 2z + 3y2 ANS . B 14. If m 3x  4 x 7 ;n 5 3 (A) 6 (C) 10 ANS . B 15. (B) 8 (D) 16 If P = x + 1 and (A) 1 (C) 2 ANS . A 16. If (A) (B) (C) (D) ANS , D and 3 (m + n) = 13 then find the value of x - 4P  3 3x  2 3   , 2 5 2 then the value of x is - (B) (D) – 1 5x 6  x 6 ( x  3) 1    , 4 8 3 6 x x then x = 121 22 121 12 x x 212 21 122 21 17. If the present age of Jacob’s father is three times that of Jacob, after five years, sum of their ages would be 70 years, then the present age of Jacob’s father is (A) 39 years (B) 45 years (C) 54 years (D) 60 years ANS . B 18. The population of town A is 4800 more than town B. If 3100 people move from town B to town A, the population of town A will be 11 times that of town B. The original total population of the two towns is (A) 12580 (B) 12780 (C) 13200 (D) 13300 ANS . C 19. If the sum of two numbers is 184 and one-third of the smaller number exceeds one-seventh of the larger number by 8, then the larger number is (A) 112 (B) 72 (C) 104 (D) 80 ANS . A 20. A person has only 25 paise and 50 paise coins. In total he has 40 coins and the value of them is Rs. 12.50. Find the number of 50 paise coins he has (A) 10 (B) 15 (C) 25 (D) 20 ANS . A 21.  Value of x in the equation x    (A) 2 (C) 6 ANS . C 22. Simplify: 4x  27  3x  4  3   2x  3 7  is - (B) 4 (D) 8 81a 2b 2c 2  64a 6b 2  144a 4 b 2c (A) a²b² [9c + 8a²]² (B) –a²b² [9c – 8a²]² 2 2 2 2 (C) a b [9c  8a ] (D) None ANS . C The degree of 3x2–9 is (A) 1 (B) 2 ANS . B 23 The expression x + y + 2 is (A) Monomial (B) Binomial ANS . C (C) 3 (D) 4 (C) Trinomial (D) None of these (C) Trinomial (D) None of these (C) 20a2b (D) 10a2b 24 25 The expression xyz is (A) Monomial ANS . A 26 (B) Binomial Add 5a2b, –8a2b and 7a2b (A) –10a2b (B) 4a2b ANS . B 27 Subtract (a2 + b2 – 2ab) from (a2 + b2 + 2ab) (A) –4ab (B) –2ab (C) 4ab (D) 2ab (a2 + b2 + 2ab) – (a2 + b2 – 2ab) = a2 + b2 + 2ab – a2 – b2 + 2ab = 4ab Sol. ANS . C The degree of a polynomial ax5 – bx4 + c is (A) 9 (B) 5 ANS . B 28 The experession 4 (x –2) + 3 (x –1) is equal to (A) 7x – 11 (B) 7x + 11 Sol. 4x – 8 + 3x – 3 = 7x – 11 ANS . A (C) 4 (D) 1 (C) 6x – 10 (D) 6x +10 29 30 Which expression is equal to 5 (2x + 1 – x – 4) ? (A) 9x – 3 (B) 5x – 15 (C) 5x – 3 Sol. 5 (x – 3) = 5x – 15 ANS . B Which one of the following is equivalent to the expression (2 5) (26)? (A) 2048 (B) 230 (C) 411 ANS . A (D) 5x + 25 31 (D) 430 32 A tanker contains 500 litres of water. Due to a small hole in the tanker, the quantity of water is decreasing at the rate of 9 litres every hour. What will be the quantity of water in the tank after 10 hours? (A) 410 litres (B) 491 litres (C) 400 litres (D) 90 litres ANS . A 33 Subtract the sum of (8a – 6a2 + 9) and (–10a – 8 + 8a2) from – 3 is (A) 2a2 – 2a – 2 (B) 2a2 – 2a + 4 (C) –2a2 + 2a – 4 (D) –2a2 + 2a – 2 Sol. –3 – (8a – 6a2 + 9 – 10a – 8 + 8a2) = –2a2 + 2a – 4 ANS . C 34 Sol. An expression is taken away from 3x2 – 4y2 + 5xy + 20 to obtain – x2 – y2 + 6xy + 20, then the expression is (A) 4x2 – 3y2 – xy (B) 2x2 – 5y2 + xy + 40 (C) 3y2 – xy – 4x2 (D) 4x2 + 3y2 + xy (3x2 – 4y2 + 5xy + 20) + X = –x2 – y2 + 6xy + 20  ANS . A 35 Sol. X = 4x2 – 3y2 – xy By how much is a4 + 4a2b2 + b4 more than a4 – 8a2b2 + b4 ? (A) 12 a2b2 (B) –12a2b2 (C) 2a4 + 2b4 a4 + 4a2b2 + b4 – (a4 – 8a2b2 + b4) = 12 a2b2 ANS . A 36 Simplify (a3 – 2a2 + 4a – 5) – (–a3 – 8a + 2a2 + 5) (A) 2a3 + 7a2 + 6a – 10 (B) 2a3 + 7a2 + 12 a – 10 (D) 10a2b2 (C) 2a3 – 4a2 + 12a – 10 (D) 2a3 – 4a2 + 6a – 10 a3 – 2a2 + 4a – 5 + a3 + 8a – 2a2 – 5 = 2a3 – 4a2 + 12a – 10 Sol. ANS . C 37 Simplify the following expression x(y –z) – y (z – x) – z (x – y) (A) 2x (y – z) (B) 2y (z – x) (C) 2x (z – y) Sol. xy – xz – yz + xy – xz + yz = 2x(y – z) ANS . A The coefficient of x2 in the expression 3x3 –7x2 + 5x + 9 is (A) 3 (B) 7 (C) –7 ANS . C (D) None of these 38 (D) 5 39 Subtract (2a – 3b + 4c) from the sum of (a + 3b – 4c), (4a – b + 9c) and (–2a + 3c – b) (A) a – 4b + 4c (B) a + 4b – 4c (C) –a + 4b + 4c (D) a + 4b + 4c Sol. (a + 3b – 4c) + (4a – b + 9c) + (–2a + 3c – b) – (2a – 3b + 4c) = (3a + b + 8c) – (2a – 3b + 4c) = 3a + b + 8c – 2a + 3b – 4c = a + 4b + 4c ANS . D If the value of 2x3 – 2x2 + x – a equals to 5, when x = 2, then the value of ‘a’ is (A) 4 (B) 5 (C) 3 (D) 6 3 2 Sol. 2(2) – 2(2) + 2 – a = 5  2(8) – 2(4) + 2 – a = 5  a=5 ANS . B 40 The value of (0.05)3 is (A) 0.000125 (B) 0.00125 ANS . A 41 The value of 7.75  0.25 is (A) 31 (B) 0.0031 ANS , A (C) 0.0125 (D) 0.125 42 43 (C) 0.31 (D) 3.1 Simplify – (A) 4xy (B) 8x2 + 18y2 (C) 8xy 2 2 2 2 (4x + 12xy + 9y ) – (4x – 12xy + 9y ) = 24 xy (D) 24xy Sol. ANS . D 44 The product of (a – b) (a + b) (a2+b2) is (A) a2 – b2 (B) a5 – b3 (C) a4 – b4 (D) a2 + b4 Sol. (a2 – b2) (a2 + b2) = a4 – b4 ANS . C 45 What is the missing term in the following product ? (2a3 – 3) (5a3–2) = 10a6 + ........+ 6 (A) 19a3 ANS . B (B) –19a3 (C) 16a3 (D) –16a3 The value of n3 + 5n2 + 5n – 2 when n = –2 is (A) 16 (B) 0 3 2 (–2) + 5(–2) + 5(–2) – 2 = 0 46 (C) –40 (D) 10 Sol. ANS . B The value of 9x2 + 49y2 – 42xy when x = 15 and y = 3 is (A) 636 (B) 576 (C) 456 (D) 386 2 2 2 2 9x + 49y – 42xy = (3x – 7y) = (3 (15) – 7(3)) = (45 – 21)2 = 576 47 Sol. ANS . B Simplify : 4st (s – t) – 6s2 (t – t2) – 3t2 (2s2–s) + 2st (s – t) (A) –st2 (B) –2st2 (C) –3st2 48 Sol. ANS 4s2t – 4st2 – 6 s2t + 6s2t2 – 6s2t2 + 3st2 + 2s2t – 2st2 = –3st2 . C 49 Divide 2x3 – 4x2 by 2x (A) x2 – 2x (B) –x2 + 4 3 (C) –x2 + 4x (D) –4st2 (D) x2 + 4 2 2x 4x   x 2  2x 2x 2x Sol. ANS . A Divide –15x5y4z3 + 10x4y4z4 + 20x3y2z by 5xyz (A) –3x4 y3 z2 – 2x3 y3 z3 + 4x2 y (B) –3x4 y3 z2 + 2x3 y3 z3 + 4x2 y 50 (C) –3x4 y3 z2 + 2x3 y3 z3 – 4x2 y 5 4 3 4 4 4  15x y z 10 x y z 20 x y z   5xyz 5xyz 5xyz = –3x4 y3 z2 + 2x3 y3 z3 + 4x2 y Sol. ANS . B 51. The value of the expression (A) 76 ANS . C 52. If 7x 7  3 6 53. n2 n  2 2 when n = 12 is (B) 74 (C) 78 (D) 72 is a polynomial, then the zero of the polynomial is 1 (A) 2 ANS . A (D) 3x4 y3 z2 – 2x3 y3 z3 – 4x2 y 3 2 (B)  1 2 If the zero of the polynomial in ‘x’ is (A) 4x – 5 (B) 5x – 4 ANS . C (C) 0  5 4 (D) – 2 , then the polynomial is (C) 5x + 4 (D) 4x + 5 1 54.  If A = – 8x2 – 6x + 10, then its value when ‘x’ 2 is (A) 6 (B) 4 (C) 5 (D) 7 ANS . C 55. The third degree polynomial among the following is (A) 2x3 – 1 + 3x2 – 1 + 5 (B) 3x4 – 1 + 2x3 – 1 + 6x2 – 1 + 8 (C) 3x– 2 – 1 + 4x– 2 + 5 (D) 2x5 – 3 + 3x4 – 3 + 7 ANS . B 56. Among the following the expression which is not a monomial is 4a 3 b 2c 5 23 (B) – 147 x3y2 (A) ANS . C 57. If , x (C) 2 2 5 x y z 7 (D) x3y5z12 then the value of 4x2 + 8x + 18 is a 2 (A) a2 + 2a + 8 (B) a2 + 3a + 18 (C) a2 + 4a + 18 5a + 18 ANS . C 58. The value of the expression  26  13x when x = 9/13 is 3 (A) – 8 ANS . B (D) a2 + 27 (B) – 10 (C) – 9 (D) – 11 Degree of the polynomial p + q xm + rxm + 2 + 5xm + 3 + xm + 4 is (A) m (B) m + 2 (C) m + 3 (D) m+ 4 ANS . C 60. If n(n  1)(2n  1) represents sum of the squares of first ‘n’ natural numbers, then 59. 6 its value when n = 10 is (A) 365 (B) 375 ANS . D 61. Degree of the polynomial (A) 4 (B) 3 ANS . C 62. Degree of the monomial (C) 395 1 5 x  3x 4  2x 3  3x 2  6 2 (C) 5 3 2 6 7 x y z 5 (D) 385 is (D) 2 is (A) 15 (B) 9 (C) 8 (D) 13 ANS . A 63. In a polynomial 3x + 5 where x = a + 2, then its value when a = 8 is (A) 25 (B) 45 (C) 35 (D) 40 ANS . C 64 The sum of 3 3 5 3 2 3 7 3 x , x ,  x and x 4 6 3 2 is 12 (A) 53 ANS . C 65 x3 (B) 53 3 x 12 (C) 53 3 x 12 (D)  12 3 x 53 The simplified form of 3x3 – 2x2 – 8x – 6x2 + 7x3 + 9x + 8x3 – 9x2 + 6x is (A) – 18x3 – 17x2 + 7x (B) 18x3 – 17x2 – 7x (C) 18x3 + 17x2 – 7x ANS . B 66  (D) 18x3 – 17x2 + 7x The ascending order of the polynomials – 3x3 + 7x2 – 9x4 + 6x – 8 is (A) – 8 + 6x + 7x2 – 3x3 + 9x4 (B) – 8 – 6x – 7x2 – 3x3 – 9x4 (C) – 8 + 6x + 7x2 – 3x3 – 9x4 (D) 8 + 6x + 7x2 + 3x3 + 9x4 ANS . A 67 If A = – 7x – 3x – 5x and B = 9x + 3x + 2x, then A + B is (A) 2x (B) – 2x (C) – x (D) – 3x ANS.C 68 If 1 x  1 x = A and 1 x  1 x = B , then A – B is 2 3 3 1 x 12 (A) ANS . A 69. (B) 4  1 x 12 (C) – 2x (D) 0 The equivalent expression of 2x3 – 3x2 – 8x – 3 is (A) 3x3 – 5x3 + 7x2 – 5x2 – 8x + 10x – 4 + 1 (B) 3x3 – x3 – 5x2 + 2x2 – 9x + x – 7 + 4 (C) 4x3 – 6x2 – 3x3 + 3x2 + x2 – 9x + 3x + 6 – 3 (D) 4x3 – 2x3 + 3x2 – 5x2 – 8x + 6x + 4 – 1 ANS . A The descending order of 4x2 – 9x3 + 3x2 – 9x4 + 3x3 – 9x2 + 6x – 3x + 5 – 3 is (A) – 9x4 + 6x3 – 2x2 + 3x + 2 (B) – 9x4 – 6x3 + 2x2 – 3x + 2 (C) – 9x4 – 6x3 – 2x2 + 3x + 2 (D) – 9x4 + 6x3 – 2x2 + 3x – 2 ANS . C 9x 3 71 If  7 x 3 + 3 x 3 + 7 x 3 + 9 x 3 is added 60 to, then the result is 70 5 4 2 3 (A) – 6x3 (B) 6x3 (C) 60x3 (D) 16x3 ANS . B 72 If 2x – 3x + 5x = P, Q = – 8x + 3x + 9x and R = – 8x – 6x – 7x, then (P + Q) – R is (A) 27x (B) 28x (C) 29x (D) 26x ANS . C 73 If A = – 3x3 – 2x3 + 4x2 – 2x2, B = – 3x2 + 5x2 – 8x + 3x and C = 2x – 9x – 7 + 8,then A + B + C in simplified form is (A) – 5x3 + 4x2 – 12x + 1 (B) 5x3 – 3x2 – 12x + 1 (C) – 5x3 – 4x2 – 12x – 1 (D) 5x3 + 3x2 + 12x + 1 ANS . A 74. If 4x3y2 + 3x2y3 – 8x2y5 is added – 9x2y3 + 6x2y5 – 9x3y4, then the result is (A) 4x3y2 + 5x2y3 – 2x2y5 – 9x3y4 (B) 4x3y2 – 6x2y3 – 2x2y5 – 9x3y4 (C) 4x3y2 – 6x2y3 + 2x2y5 – 9x3y4 (D) – 4x2y2 – 6x2y3 – 2y2y5 – 9x3y4 ANS . B 75. If 0.5x3 + 1.85x3 + 2.96x3 – 4.71x3 is added to (1.25 x4 – 2.5x5 + 3.6x4 – 4.71x(D), then the result is (A) 0.6x3 + 2.36x4 (C) 0.6x3 – 2.36x4 ANS . C (B) – 0.6x3 – 2.36x4 (D) – 0.6x3 + 2.36x4 If B = – 9x2 + 3x – 7, then the additive inverse of B is (A) 9x2 – 3x – 7 (B) 9x2 – 3x + 7 (C) – 9x2 – 3x – 7 3x + 7 ANS . B 1 2 1 2 77. If A 3x + 2 x + 7 = and B 4 x  3 x + 8 =, then A – B is 76. 4 (D) – 9x2 + 3 (A) x2 – x + 1 (B) – x2 – x – 1 (C) – x2 + x – 1 (D) x2 + x + 1 ANS . C 1 3 3 2 5 7 x  x  x+ 78. If P = 2x3 – 3x2 – 5x + 6 and Q =, then Q – P is 3 (A) 5x 3 9x 2 5x 11    3 4 2 3 (C) ANS . B 79. If (A) (C) ANS . D 5x 3 9x 2 5x 11    3 4 2 3 A= 3 3 9 2 6x x  x + +2 2 7 7 3x 3 9 2 6x  x  2 2 2 7 3x 3 9 2  x  6x  2 2 2 (B) 4 2 3 5x 3 9x 2 5x 11    3 4 2 3 (D) 5x 3 9x 2 5x 11    3 4 2 3 and A + B = 0, then polynomial B is (B) (D) 3x 3 9 2 6x  x  2 2 2 7 3x 3 9 2 6x  x  2 2 7 7 If A = 2x3 – 9x2 – 6x + 7 and A + B = 5x3 – 6x2 – 8x + 9, then the polynomial (A + (B) – A is (A) 3x3 – 3x2 – 2x + 2 (B) 3x3 + 3x2 – 2x + 2 (C) 3x3 + 3x2 + 2x + 2 (D) – 3x3 – 3x2 – 2x + 2 ANS . B 81. If A = 4x3 – 9x2 – 9x – 8 and A – B = – 2x3 – 8x2 – 6x – 2, then the polynomial B = A – (A – (B) is (A) 6x3 – x2 – 3x – 6 (B) 6x3 + x2 + 3x + 6 80. (C) 6x3 + x2 + 3x – 6 (D) ANS . A 82 Given A = 2x3 – 3x2 + 6x + 7 and B = 4x3 inverses of A and B, then D – C is (A) – 2x3 + 6x2 + 9x (B) 3 2 (C) – 2x – 6x + 9x (D) – 6x3 – x2 – 3x – 6 – 9x2 – 3x + 7, If C, D are additive – 2x3 + 5x2 + 9x – 2x3 – 6x2 – 9x ANS . A 83. If A – B = 2x3 – 3x2 + 8x – 7 and B = 5x3 – 9x2 + 6x – 8, where A = (A – (B) + B, then the polynomial A is (A) 7x3 – 12x2 + 14x + 18 (B) 7x3 – 12x2 + 14x – 15 (C) 7x3 – 12x2 – 14x + 15 (D) – 7x3 + 12x2 – 14x – 15 ANS . B 5 7 3 84 Given C  x 2  x  and C + A = 0. If 6 6 2 the result is (A) x2 – x + 1 ANS . C (B) – x2 – x – 1 B= x2 1 1  x+ 6 6 2 (C) x2 + x – 1 is added to A, then (D) x2 – x + 1 If A = 7x3 – 2x2 – 9x + 6, B = 2x3 – 8x2 + 3x – 5, C = 2x3 – 4x2 – 8x + 7, and D = – 3x3 – 5x2 + 6x + 7, then (A – (C) – (B – (D) is (A) 5x2 – 2x – 11 (B) 5x2 + 2x + 11 (C) 5x2 – 2x + 11 (D) – 5x2 – 2x – 11 ANS . B 86. The value of (3p – (A)3p + 5 is =_______ (A) 9p2–12p+5 (B) 9p2+12p–5 (C) 4p2+12p–5 (D)9p2–12p–5 85. ANS . D 87. The value of (t/2+6)(t/3–(B) is =_______ t3 3t2   12 4 2 (A) ANS . B (B) t 4 3t   18 4 2 (C) t3 3t2   18 4 2 The value of (497)2 is ____( using the indentity ) (A) 247006 (B) 247009 (C) 257006 ANS . B 2 1 1  89 The expansior of is  x 2 y  2  _________ (D) t3 3t2   18 4 2 88. 2 (A) (C) ANS . B 90 1 4 x 1 x y  4 3y 9x 2 y 4 1 4 2 x 1 x y   4 3y 9x 2 y 4 (B) 3xy  1 4 2 x 1 x y   4 3y 9x 2 y 4 (D) x4 y2  The expanssion of (3.2d–5f)2 is ______________ 1 1  xy 9x 2 y 4 (D) 2578009 (A) 10.24d2+32df+25f2 (C) 10.24d2–32df+25f2 (B) 10.24d2–25f2+32df (D)10.24d2–32df–25f2 ANS . C 91. Without actual multiplication, the value of (1001×1007) is =_______ (A) 10008007 (B) 1080007 (C) 10080007 (D) 1008007 ANS . D 92. Without actual multiplication, the value of (79.01×79.0(A)+2×79.01×20.99+(20.99×20.99) is =______ (A) 10009 (B) 1000.05 (C) 10000 (D) 10007 ANS . C 93. If (4x – 3 – 2x + 7)( – 3x – 4 + 5x + (A) is simplified, then the answer is _ (A) 4x2 + 2x – 12 (B) 14x2 – 22x + 12 (C) 4x2 + 2x + 12 (D) – 14x2 – 2x – 12 ANS . A 94 If (x + 7)(x + (C) + (x – (B)(x + 5) is simplified , then the answer is _______ (A) 2x2 + 13x + 11 (B) 2x2 – 13x + 11 (C) 2x2 – 13x – 11 (D) – 2x2 – 13x – 11 ANS . A 95. (12x3+(A)2+(6x3–(C)2=___________________ (A) 180x6–12x3+10 (B) 180x6+12x3+10 (C) 180x6–12x3–10 (D) 180x6+12x3–10 ANS . A 96. If A= 1002+100(5+(C)+5×3 and B= 1002–100(8+(C)+8×3, then A+B=_____ (A) 19735 (B) 19736 (C)19739 (D)19732 ANS . C 1  3 1 3 97. For the product  p    p   is the value obtained by using the identity is 5 3 5 3   _____ 9p2 1  25 9 1 9p2  9 25 9p2 1  25 9 16  x4 625 16  x4 625 x4  3p2 1  5 3 (A) (B) (C) (D) ANS . C 98. Using the identity the value obtained from the product 25.4×24.6 is (A) 62.84 (B) 624.84 (C) 642.84 (D)264.84 ANS . B 99. Using the identity (a+b)(a–b) = a2 – b2, the value obtained from the product (2/5+x)(2/5–x)(4/25+x(B) is ____ (A) ANS . A (B) (C) 16 625 (D) x4  16 625 100. If (x – 3y)(x + 3y)(x2 + 9y(B) is simplified, then the answer is _____ (A) x4 + 81y4 (B) – 81y4 + x4 (C)x4 – 81y4 (D) – x4 – 81y4 ANS . C