麻烦解个方程1200-80x-90x+6x^2=198

问题描述:

麻烦解个方程
1200-80x-90x+6x^2=198

6x^2-80x-90x+1002=0
x1 = 19.97136 ,x2 = 8.361975

1200-80x-90x+6x^2=198
6x²-170x+1002=0
3x²-85x+501=0
x=[85±√(7225-6012)]/6=[85±√(1213)]/6≈20;8.4.