Answer:
x = 0
Step-by-step explanation:
x + 20 + 10x = 20 + 9x
combine like terms
20 + 11x = 20 + 9x
-20 from both sides
11x = 9x
-9x from both sides
2x = 0
/2 from both sides
x = 0/2
0/2 = 0