设甲为x 乙为y,可列方程
x-20=y 3(x+12)/16=(y-12)/4 3(x+12)=4(y-12) 3(x+12)=4(x-20-12) 3(x+12)=4(x-32) 3x+36=4x-128 ∴甲=164 乙=144