(x-2y-1)(x-0.5y+1)-(x-0.5y-1)的平方,其中x=1.7 y=3.9

问题描述:

(x-2y-1)(x-0.5y+1)-(x-0.5y-1)的平方,其中x=1.7 y=3.9

=(x-2y)(x-0.5y+1)-(x-0.5y+1)-(x-0.5y-1)
=(x-2y)(x-0.5y+1)-(2x-y)
=(-6.1)×0.75-(-5)
=3.7625