x-4/5x=20 1/5x=20 x=20*5 x=100 2/3x+1/2x=49 (2/3+1/2)x=49 (7/6)x=49 x=49÷(7/6) x=42 75+7/10x=102 7/10x=102-75=27 x=27÷(7/10) x=270/7 2x+9/2=12 2x=12-9/2=15/2 x=(15/2)÷2 =15/4
