解方程组：x+1/3-y+2/4=0 x-3/-y-3/3=1/12

解方程组：x+1/3-y+2/4=0 x-3/-y-3/3=1/12
解方程组：x+1/3-y+2/4=0 x-3/-y-3/3=1/12

解方程组：x+1/3-y+2/4=0 x-3/-y-3/3=1/12
x-3/-y-3/3=1/12 两边乘3
x-3-y+3=1/4
y=x-1/4
x+1/3-y+2/4=0 两边乘12
4（x+1）-3(y+2)=0
4x+4-3y-6=0
4x-3y=2
4x-3(x-1/4)=2
4x-3x+3/4=2
x=2-3/4
x=5/4
y=x-1/4=5/4-1/4=1