2x -1 + x + x + 1= 180
2x+x+x-1+1=180 ( combine like terms)
2x+2x-1+1=180
-1+1=0
2x+2x+0=180
4x+0=180
4x=180
divide both sides by 4 to get x by itself
4x/4=180/4
x=180/4
Answer: x=45
6.5m questions
8.6m answers