Question

Solve for a
T
U
4x 10
12x + 151
S

Answer 1

x = 10

Explanation:

The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.

12x + 15 is an exterior angle of the triangle , then

12x + 15 = 4x + 10 + 85 , that is

12x + 15 = 4x + 95 ( subtract 4x from both sides )

8x + 15 = 95 ( subtract 15 from both sides )

8x = 80 ( divide both sides by 8 )

x = 10