Question

1)   Thực hiện phép tính

a)    (2x – 1)² – 4 (x – 1)(x + 1) – (x – 2)(x + 3)

b)   (2x + 3)(4x² – 6x + 9) – 8x(x – 3)(x + 3)

Answer 1

\(a,=4x^2-4x+1-4x^2+4-x^2-x+6=-x^2-5x+11\\ b,=8x^3+27-8x^3+72x=72x+27\)

Answer 2

a) \(=4x^2-4x+1-4\left(x^2-1\right)-\left(x^2-2x+3x-6\right)=4x^2-4x+1-4x^2+4-x^2-x+6=-x^2-5x+11\)

b) \(=8x^3+27-8x\left(x^2-9\right)=8x^3+27-8x^3+72x=72x+27\)