It is indeed the rearranging of neuritis to the ground.
Theorem
In a triangle, the measure of an exterior angle equals the sum of the measures of its two remote interior angles.
x + y = z
4n - 18 + n + 8 = 133 - 6n
5n - 10 = 133 - 6n
11n = 143
n = 13
z = 133 - 6n = 133 - 6(13) = 133 - 78 = 55
Answer: C. 55
Your calculator says error because you cant have a square root of a negative number because there is no solution to that maybe recheck your equation and try again
6/14=x/20 cross multiply and get 14x=120 divide and get 8 2/30
