已知-x+2y=5,那么5(x一2y)∧2一3(x一2y)一60的值为( ) A已知-x+2y=5,那么5(x一2y)∧2一3(x_数学解答

已知-x+2y=5,那么5(x一2y)∧2一3(x一2y)一60的值为( ) A
已知-x+2y=5,那么5(x一2y)∧2一3(x一2y)一60的值为( ) A -17 B -7 C -3 D 7

人气：217 ℃　时间：2020-03-22 07:07:29

解答

-x+2y=5
∴x-2y=-5
5(x一2y)∧2一3(x一2y)一60
=5×(-5)^2-3×(-5)-60
=125+15-60
=80这是一道选择题，答案中没80说明题目错了呀