Q3 of 59 Page 7

Using algebraic identities find the coefficients of x2 term, x term and constant term.

(2x + 3)(2x + 5)(2x + 7)

(2x + 3)(2x + 5)(2x + 7)


Here we have to use the identity


(x + a)(x + b)(x + c) = x3 + (a + b + c)(x)2 + (ab + bc + ca)x + abc


∴ (2x + 3) (2x + 5)(2x + 7)


= (2x)3 + 4(3 + 5 + 7)x2 + (15 + 35 + 21)2x + 105


= 8x3 + 60x2 + 142x + 105


Coefficient of


x2 = 60


x = 142


Constant term = 105


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