1.2y=1-3/2*x
y=1/2-3/4*x
2.7/4*y=2-1/4*x
y=8/7-1/7*x
3.-5y=-4x
y=4/5x
4.6y-6=6x+4
6y=6x+10
y=x+5/3
1把y=x+3带入7x+5y=9,得
7x+5(x+3)=9
解得x=-1/2
带入y=x+3得y=5/2
1.2y=1-3/2*x
y=1/2-3/4*x
2.7/4*y=2-1/4*x
y=8/7-1/7*x
3.-5y=-4x
y=4/5x
4.6y-6=6x+4
6y=6x+10
y=x+5/3
1把y=x+3带入7x+5y=9,得
7x+5(x+3)=9
解得x=-1/2
带入y=x+3得y=5/2