求方程组0.5x+0.8y=4.7 0.6x+0.12y=6.6
问题描述：
求方程组0.5x+0.8y=4.7 0.6x+0.12y=6.6
答
6(0.5x+0.8y)=28.2……5(0.6x+0.12y)=33……相减得：y=-(8/7);x=131/70
答
0.5x+0.8y=4.7.(1)
0.6x+0.12y=6.6.(2)
(1)*6:
3x+4.8y=28.2.(3)
(3)*5:
3x+0.6y=33.(4)
(3)-(4):
4.2y=-4.8
y=-8/7
代入(1):
x=393/35
综上所述,
{x=393/35
{y=-8/7