Hi!
3x - 30 = x + 10
Solve by isolating x on one side.
Add 30 to both sides.
3x - 30 + 30 = x + 10 + 30
3x = x + 40
Subtract x from both sides.
3x - x = x - x + 40
2x = 40
Divide by 2 on both sides
2x/2 = 40/2
x = 20
The answer is x = 20
Hope this helps! :)
-Peredhel