a) 10x-50=100
1. Add 50 to both sides, 10x-50+50=100
10x=150
2. Divide both sides by 10, 10x/10=150/10
3. This means that x=15
b) 3/4x+10=20
1. Multiple both sides by 4
2. Move the constant to the right, 3x+40=80
3. Subtract the numbers, 3x= 80-40
4. 3x=40 Divide both sides by 3
5. This mean that x= 40/3
c) 1/2(x-7)=20
1. Multiple both sides by 2
2. Move the constant to the right, x-7=40
3. Add the numbers, x=40+7
4. This means that x=47
I hope this helps!!