问题 选择题

已知-x+3y=5,则5(x-3y)2-8(x-3y)-5的值为(  )

A.80

B.-170

C.160

D.60

答案

∵-x+3y=5,

∴x-3y=-5,

∴5(x-3y)2-8(x-3y)-5

=5×(-5)2-8×(-5)-5

=125+40-5

=160.

故选C.

判断题
判断题