已知-x+3y=5 求5(x-3y)²-8(x-3y)-5

问题描述:

已知-x+3y=5 求5(x-3y)²-8(x-3y)-5


-x+3y=5
∴x-3y=-5

原式
=5×(-5)²-8×(-5)-5
=125+40-5
=160