1.(x+1)(x+2)-x-10

问题描述:

1.(x+1)(x+2)-x-10
2.(x2-2x(x2-2x-4)+4
3.x2-3xy-18y2-3x-9y
2.(x2-2x)(x2-2x-4)+4

1.(x+1)(x+2)-x-10
=x^2+2x+x+2-x-10
=x^2+2x-8
=(x-2)(x+4)
2.(x2-2x(x2-2x-4)+4
你把题写清楚
3.x2-3xy-18y2-3x-9y
=x^2-3xy-18y^2-3(x+3y)
=(x-6y)(x+3y)-3(x+3y)
(x+3y)(x-6y-3)