Answer:
Step-by-step explanation:
9
The angles are vertically opposite. Vertically opposite angles are equal.
12x - 5 = 10x + 1 Add 5 to both sides.
12x = 10x + 5 + 1 Combine
12x = 10x + 6 Subtract 10x from both sides.
12x - 10x = 6 Combine
2x = 6 Divide by 2
x = 6/2
x = 3
10
Adjacent angles to each other when sharing a side are supplementary
4x + 7 + 2x + 5 = 180 Combine like terms on the left
6x + 12 = 180 Subtract 12 from both sides
6x = 180 - 12 Combine
6x = 168 Divide by 6
x = 168 / 6
x = 28
