Question

Tính(rút gọn)

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

2) -4x(x+3)(x-4)-3x(x^2-x+1)

Answer 1

\(1,=-x^2+2x+15+2x^2+5x-3=x^2+7x+12\\ 2,=-4x\left(x^2-x-12\right)-3x^3+3x^2-3x\\ =-4x^3+4x^2+48x-3x^3+3x^2-3x\\ =-7x^3+7x^2+45x\)

Answer 2

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

=(x+3)(-x+5+2x-1)=(x+3)(x-4)\(=X^2-4x+3x-12=x^2-x-12\)

\(2) -4x(x+3)(x-4)-3x(x^2-x+1)=(-4x^2-12x)(x-4)-3x^3+3x^2-3x=-4x^3-12x^2-12x^2+48x-3x^3+3x^2-3x=-7x^3-12x^2-45x\)