Answer:
x = 35
Explanation:
Angles sum of a triangle = 180
That being said we want to create an equation to solve for x
180 = 2x - 8 + x - 7 + 90 ( there is a right angle indicated by the little square; a right angle has a measure of 90 degrees, so just in case you were wondering that's where the 90 came from )
now we solve for x
step 1 combine like terms
2x + x = 3x
90 - 7 - 8 = 75
now we have 180 = 75 + 3x
step 2 subtract 75 from each side
180 - 75 = 105
75 - 75 cancels out
Now we have 105 = 3x
step 3 divide each side by 3
105 / 3 = 35
3x/3=x
we're left with x = 35