Question

7(x-1)2+4(x-1)(y+2)-20(y+2)2 8x2y2+6xy-35 2(a+b)2+(a+b)(a-b)

Answer 1

7(x-1)^2+4(x-1)(y+2)-20(y+2)^2

=[7(x-1)-10(y+2)][(x-1)+2(y+2)]

=(7x-7-10y-20)(x-1+2y+4)

=(7x-10y-27)(x+2y+3)

其他的我不会了~抱歉~