Question

Giải cho mỉnh câu 3 và câu 6 với

Answer 1

3) \(2x\left(10x^2-3x-2\right)-5x\left(4x^2-2x-1\right)=20x^3-6x^2-4x-20x^3+10x^2+5x=4x^2+x\)

6) \(8x\left(5-2x\right)+\left(8x+1\right)\left(2x-5\right)=8x\left(5-2x\right)-\left(8x+1\right)\left(5-2x\right)=\left(5-2x\right)\left(8x-8x-1\right)=-\left(5-2x\right)=2x-5\)

Answer 2

\(1,=-2x^4+3x^2-x\\ 2,=6x^2y^3-15x^2y^2-12xy\\ 3,=20x^3-6x^2-4x-20x^3+10x^2+5x=4x^2+x\\ 4,=x^2+4x-21-x^2+x=3x-21\\ 5,=4x^2-7x-2-4x^2+7x=-2\\ 6,=40x-16x^2+16x^2-38x-5=2x-5\)