Đáp án+Giải thích các bước giải:
`1)-3x(x+2)^2+(x+3)(x-1)(x+1)-(2x-3)^2`
`=-3x(x^2+4x+4)+(x+3)(x^2-1)-(4x^2-12x+9)`
`=-3x^3-12x^2-12x+x^3-x+3x^2-3-4x^2+12x-9`
`=-2x^3-13x^2-x-12`
`2)(x-3)(x+3)(x+2)-(x-1)(x^2-3)-6x(x+4)^2`
`=(x^2-9)(x+2)-(x^3-3x-x^2+3)-6x(x^2+8x+16)`
`=x^3+2x^2-9x-18-x^3+3x+x^2-3-6x^3-48x^2-96x`
`=-6x^3-45x^2-102x-21`
`3)2x(x-4)^2-(2x+5)(x-2)(x+2)+2(x+5)^2`
`=2x(x^2-8x+16)-(2x+5)(x^2-4)+2(x^2+10x+25)`
`=2x^3-16x^2+32x-2x^3+8x-5x^2+20+2x^2+20x+50`
`=-19x^2+60x+70`
`4)(x+5)^2-4x(2x+3)^2+(4x-2)(2x-3)(2x+3)`
`=(x^2+10x+25)-4x(4x^2+12x+9)+(4x-2)(4x^2-9)`
`=x^2+10x+25-16x^3-48x^2-36x+16x^3-36x-8x^2+18`
`=-55x^2-62x+43`
