Question

帮忙算一道数学题2（x-2y）2-4（2y-x）+（x-2y）2-3（x-2y） 其中x=-1 y=1/2

Answer 1

2(x-2y)²-4(2y-x)+(x-2y)²-3(x-2y)

=2(x-2y)²+4(x-2y)+(x-2y)²-3(x-2y)

=3(x-2y)²+(x-2y)

=(x-2y)(3x-6y+1)

=(-1-1)*(-6+1)

=10