2x - 5 + 3x = 35
We must combine like terms.
2x + 3x = 5x
-5 + 5x = 35
Do the opposite of what the non-x number is (the non-x number is -5, opposite is +5)
-5 + 5 + 5x = 35 + 5
5x = 40
5x is the same as 5 times x, and the opposite of multiplication is division.
5x/5 = 40/5
x = 8