已知-x+2y=5,那麼5(x-2y)2-3(x-2y)-60的值為______.

已知-x+2y=5,那麼5(x-2y)2-3(x-2y)-60的值為______.

∵-x+2y=5,∴x-2y=-5,∴5(x-2y)2-3(x-2y)-60=5×(-5)2-3×(-5)-60=125+15-60=80.故答案是80.