Answer: x=40
Explanation:
x+2x+x+20=180
first you combine the like terms which are (x, 2x, x) and get 4x.
now you have 4x+20=180
next you subtract 20 on both sides:
4x+20=180
-20 -20
and get 4x=160
finally you divide 4 on both sides and get a final answers of x=40