Answer:
x = 33
Step 1:
First, let's add the values together from both parentheses.
2x + x = 3x
1 + (-10) = -9
Now we are left with:
3x - 9 = 90.
Step 2:
Add 9 on the left side to cancel out the 9. Add it to the right side.
3x = 99
Finally, divide both sides by 3 to get our answer.
3x / 3 = x
99 / 3 = 33
x = 33
