Đáp án:
`d)-x²-8x+10`
`e)-4y²+3xy`
`f)-2ab+b²-2a-1`
`g)5x²+24x-5`
Giải thích các bước giải:
`d)2x(x-3)+(x-1)²-(2x+3)(2x-3)`
`=2x²-6x+x²-2x+1-(4x²-9)`
`=2x²-6x+x²-2x+1-4x²+9`
`=(2x²+x²-4x²)+(-6x-2x)+(1+9)`
`=-x²-8x+10`
`e)(x-2y)(x+2y)-x(x-3y)`
`=x²-4y²-x²+3xy`
`=(x²-x²)-4y²+3xy`
`=-4y²+3xy`
`f)(a-b)²-(a+1)²`
`=a²-2ab+b²-(a²+2a+1)`
`=a²-2ab+b²-a²-2a-1`
`=(a²-a²)-2ab+b²-2a-1`
`=-2ab+b²-2a-1`
`g)(3x+2)²-(2x-3)²`
`=9x²+12x+4-(4x²-12x+9)`
`=9x²+12x+4-4x²+12x-9`
`=(9x²-4x²)+(12x+12x)+(4-9)`
`=5x²+24x-5`