9/10-3+x=3/4x=3/4-9/10+3=27/40-36/40+3=-9/40+3=2又31/40
9/10-3+x=3/4解:x=3/4-9/10+3=27/40-36/40+3=-9/40+3=2又31/40
9/10-3+x=3/4解方程:x=3/4+3-9/10x=15/20+60/20-18/20x=75/20-18/20x=57/20