当2y-x=5时,5(x-2y)²-3(-x+2y)-60=________ (过程列出来)

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当2y-x=5时,5(x-2y)²-3(-x+2y)-60=________ (过程列出来)

当2y-x=5时,5(x-2y)²-3(-x+2y)-60=________ (过程列出来)
当2y-x=5时,5(x-2y)²-3(-x+2y)-60=________ (过程列出来)

当2y-x=5时,5(x-2y)²-3(-x+2y)-60=________ (过程列出来)

2y-x=5
∴x-2y=-5
∴5(x-2y)²-3(-x+2y)-60
=5(x-2y)²+3(x-2y)-60
=5×(-5)²+3×(-5)-60
=125-15-60
=50