x+1/3x=4/54/3x=4/5x=4/5×3/4x=3/5
x+1/3 x=4/54/3 x=4/5x=3/5
x+1/3*x=4/5解:4/3*x=4/5x=3/5
x+(1/3)x=4/5(4/3)x=4/5x=3/5