2/3x+3/4y=0.54/5x+5/6y=7/154(x-y-1)=3(1-y)-23x+y=9

Question

2/3x+3/4y=0.5
4/5x+5/6y=7/15
4(x-y-1)=3(1-y)-2
3x+y=9

Answer 1

2/3x+3/4y=0.5
4/5x+5/6y=7/15
通分得：8x+9y=6
24x+25y=14
解之得：x=- 3/2 y=2

4(x-y-1)=3(1-y)-2
3x+y=9
整理得：4x-y=5
3x+y=9
解之得：x=2 y=3