解方程:5/8x(x-0.3)=75%
问题描述：
解方程:5/8x(x-0.3)=75%
答
5/8x(x-0.3)=75%
两边乘8/5
x²-0.3x=6/5
x²-3x/10+9/400=6/5+9/400
(x-3/20)²=489/400
x-3/20=±√489/20
x=(3-√489)/20,x=(3+√489)/20........