100 − x + 300 = 200
1: Simplify both sides of the equation.
100 − x + 300 = 200 100 + −x + 300 = 200 (−x) + (100 + 300) = 200
(Combine Like Terms)
−x + 400 = 200 −x + 400 = 200
2: Subtract 400 from both sides.
−x + 400 − 400 = 200 − 400 −x = −200
3: Divide both sides by -1.
−x −1 = −200−1
x = 200
