x-3/7=1/2
x=3/7+1/2
x=6/14+7/14
x=13/14
x+2/3=14/9
x=14/9-2/3
x=14/9-6*9
x=8/9
x-5/6=1/3
x=5/6+1/3
x=5/6+2/6
x=7/6