Answer:
x = 10 , y = 5
Explanation:
15x and 3x are a linear pair and sum to 180° , then
15x + 3x = 180
18x = 180 ( divide both sides by 18 )
x = 10
Then
15x = 15 × 10 = 150
10(x + y) and 15x are vertically opposite angles and are congruent (equal), so
10(x + y) = 150 ( divide both sides by 10 )
x + y = 15 ( substitute x = 10 into the equation )
10 + y = 15 ( subtract 10 from both sides )
y = 5
solution is x = 10 and y = 5