已知:x+y=-5,求5(x-3)+5y+12-3(x+y)的二次方的值
问题描述:
已知:x+y=-5,求5(x-3)+5y+12-3(x+y)的二次方的值
答
5(x-3)+5y+12-3(x+y)的二次方
=5x-15+5y+12-3(x+y)²
=5(x+y)-3-3(x+y)²
=5×(-5)-3-3×(-5)²
=-103