Question

Solve [3/2x + 1]^3 with suitable identity

Answer 1

this is forming an identity

(a-b)3=a3-b3-3ab(a-b)

so

(2x-1)3=(2x)3-(1)3-3×(2x)×(1)(2x-1)

(2x-1)3=8x3-1-6x(2x-1)

(2x-1)3=8x3-1-12x2+6x

Answer 2

a=3/2x, b= 1

(3/2x+1)^3=(3/2x)^3+3(3/2x)^2(1)

+3(3/2x)(1)^2+ (1)^3

= 27/8x^3+27/4x^2+9x/2+1