解方程组0.5x+0.8y=4.7 0.6x+1.2y=6.6要有过程

Question

如题所述

Answer 1

5x+8y=47 (1)
6x+12y=66 (2)
x+2y=11 (2)' 解出：x=11-2y 代入(1)得到： 5(11-2y)+8y=47
55-10y+8y=47
2y=8
y=4
x=11-2*4=3
即：x=3
y=4
验证：将x=3,y=4 代入(1)(2)正确无误！

Answer 2

0.5x+0.8y=4.7两边同乘以10得5x+8y=47.........*
0.6x+1.2y=6.6两边同除以0.6得x+2y=11..........#
(5#)-*得2y=8 y=4代入#得x=3