Adding all of these should equal to 180 from the way the angle is set up.
So the equation should be:
(3x + 2) + (2x + 5) + (2x - 9) = 180
You can remove parentheses as it doesn’t affect the equation since it is all addition.
Let’s first add the common variables together.
3x + 2x + 2x = 7x
2 + 5 + (-9) = -2
So now we should have:
7x - 2 = 180
Now add 2 to both sides.
7x = 182
Divide both sides by 7 to isolate x.
x = 26
So x is 26.