8（3-x）²-72＝0 5x²-3x+2＝0

8（3-x）²-72＝0 5x²-3x+2＝0
8（3-x）²-72＝0 5x²-3x+2＝0

8（3-x）²-72＝0 5x²-3x+2＝0
8（3-x）²-72＝0
(x-3)²=9
x-3=±3
x=0,x=6
5x²-3x+2＝0
判别式小于0,无解
若是5x²-3x-2=0
(5x+2)(x-1)=0
x=-2/5,x=1