0.75+x=1又3分之13/4+x=4/3x=4/3-3/4x=7/12
0.75+x=1又3分之1，3/4X+X=4/3 7/4X=4/3 X=16/21
3/4+x=4/3x=4/3-3/4x=7/12
7/12
