6х-6хy-8x+8y при х=-4,у=2

Question

6х-6хy-8x+8y при х=-4,у=2

Answer 1

6х-6ху-8х+8у=6х-8х-6ху+8у=-2х-6ху+8у, при Х=-4, у=2
-2*(-4)-6*(-4)*2+8*2=8+28+16=52

Answer 2

-2x -6xy+8y= -2(x+3y-4y) =-2(-4+3×2-4×2)=( -2) ×(-6)= 12