Answer:
a = 14
Explanation:
The angles share a common side terminal side, so they are supplementary angles. This also means they add up to 180º.
8a + (5a - 2) = 180
Combine like terms.
13a - 2 = 180
13a = 182
Divide both sides by 13.
a = 14
This is your answer.
Check your work by plugging "a" back into the original equation.
8a + (5a - 2) = 180
8(14) + [5(14) - 2] = 180
112 + (70 - 2) = 180
112 + 68 = 180
180 = 180
Your answer is correct.
Hope this helps!