Question

Thực hiện phép tính

a,(x-2)(x+3)-x(x+2)-3(2x-1)

b,(3x+1)(2x-1)-(x-4)(2x+5)

c,(3-x)(5x+2)+(3x-2)(1-x)

Answer 1

a, \(=x^2+x-6-x^2-2x-6x+3=-7x-3\)

b, \(=6x^2-x-1-2x^2+3x+20=4x^2+2x+19\)

c, \(=15x+6-5x^2-2x+3x-3x^2-2+2x=-8x^2+18x+4\)

Answer 2

a.

\(=x^2+3x-2x-6-x^2-2x-6x+3\)

\(=-7x-3\)

b.

\(=6x^2-3x+2x-1-2x^2-5x+8x+20\)

\(=4x^2+2x+19\)