## Prealgebra (7th Edition)

-9 +20 =19x -4 - 18x Simplify both sides 11 = x -4 Add 4 to both sides 11+4=x-4+4 Simplify 15=x The solution is 15 Check -9 +20 =19x -4 - 18x -9+20 =19$\times$ 15- 4 - 18$\times$ 15 11 = 295 -4 -280 Simplify 11=11