Answer:
y = 57
Step-by-step explanation:
Given that Savannah has proven that angle A and angle B are congruent, it follows that their measures are equal.
This means, m<A = m<B.
First, let's find the value of x.
(139)° + (x + 8)° = 180° (angles on a straight line/linear pair)
139 + x + 8 = 180
Combine like terms
139 + 8 + x = 180
147 + x = 180
Subtract 147 from each side
147 + x - 147 = 180 - 147
x = 33
Since angle A = angle B, therefore,
3x - y = x + 8
Plug in the value of x
3(33) - y = 33 + 8
99 - y = 42
Collect like terms
99 - 42 = y
57 = y
y = 57
