Answer:
m∠BOC = 60°
Explanation:
m∠AOB and m∠BOC have to add up to m∠AOC.
Step 1: Define
m∠AOB = 7x + 30
m∠BOC = 9x + 42
m∠AOC = 104
Step 2: Set up
7x + 30 + 9x + 42 = 104
Step 3: Solve for x
Combine like terms: 16x + 72 = 104
Subtract 72 on both sides: 16x = 32
Divide both sides by 16: x = 2
Step 4: Find m∠BOC
m∠BOC = 9(2) + 42
m∠BOC = 18 + 42
m∠BOC = 60°