Question

Phân tích thành nhân tử bằng phương pháp đặt nhân tử chung:

a) 3x(x-a) + 4a(a - x)

b) 2x(x + 1) - x -1

Answer 1

a, 3x(x-a)+ 4a(a-x)

=3x(x-a)-4a(x-a)

=(3x-4a)(x-a)

b,2x(x+1)-x-1

=2x(x+1)-(x+1)

=(2x-1)(x+1)

Answer 2

\(a.3x\left(x-a\right)+4a\left(a-x\right)\)

\(=3x\left(x-a\right)-4a\left(x-a\right)=\left(x-a\right)\left(3x-4a\right)\)

b) \(2x\left(x+1\right)-x-1=2x\left(x+1\right)-\left(x+1\right)\)

\(=\left(x+1\right)\left(2x-1\right)\)