x-3分之2=5分之1 x+20分之35=3 x-7分之5=14分之3
x-2/3=1/5 x+35/20=3 x-5/7=3/14
x=1/5+2/3 x=3-35/20 x=3/14+5/7
x=13/15 x=25/20 x=5/7