Two angles lie along a straight line. If m∠A is five times the sum of m∠B plus 7.2°, what is m∠B?

Answer

The answer is 28.8

Answer: 28.8°

Step-by-step explanation:

∠A = 5 (∠B) + 7.2°

∠B = ∠B

Since they are on a straight line, they form a linear pair (sum = 180°)

∠A + ∠B = 180°

Use Substitution:

5 (∠B) + 7.2° + ∠B = 180°

Add like terms:

6 (∠B) + 7.2° = 180°

Subtract 7.2° from both sides:

6 (∠B) = 172.8°

Divide both sides by 6:

∠B = 28.8°