Answer:
x = 9
Explanation:
the exterior angle of a triangle is equal to the sum of the two opposite interior angles.
∠ QPE is an exterior angle of the triangle , then
∠ QPE = ∠ PQR + ∠ PRQ
substitute the values for the angles into the equation and solve for x
80 = 6x - 5 + 13 + 2x ( simplify right side )
80 = 8x + 8 ( subtract 8 from both sides )
80 - 8 = 8x + 8 - 8 ( simplify both sides )
72 = 8x ( divide both sides by 8 )
=
x , that is
9 = x