Answer:
x = 16
Explanation:
The angles shown are vertical angles
Vertical angles are congruent ( equal to each other )
Thus, 85 = 4x + 21
( we now solve for x )
85 = 4x + 21
step 1 subtract 21 from each side
21 - 21 cancels out
85 - 21 = 64
we now have 64 = 4x
step 2 divide each side by 4
64 / 4 = 16
4x / 4 = x
we're left with x = 16