Answer:
x = 47
Step-by-step explanation:
180 = x + (180 - 107) + (x + 13)
Subtract in the parenthesis.
180 = x + 73 + x + 13
Combine terms.
180 = 2x + 86
Subtract 86 from both sides.
2x = 94
Divide both sides by 2.
x = 47.
Proof:
180 = x + (180 - 107) + (x + 13)
180 = 47 + (180 - 107) + (47 + 13)
180 = 47 + 73 + 60
180 = 120 + 60
180 = 180
