Hello from MrBillDoesMath!
Answer: Using the diagram provided the question can not be answered.
Discussion:
The 3 angles of a triangle add up to 180. From the diagram
73 + ( 6x + 4) + ( 8y -7) = 180
This equation has two variables, x and y, and we can't solve it as such. BUT if the third angle was intended to be (8x -7), an assumption totally, then
73 + ( 6x + 4 ) + ( 8x -7) = 180 or
73 + (6x + 8x) + (4 -7) = 180 or
73 + 14x -3 = 180 or
14x + 70 = 180 or
14x = 180 -70 = 110
x = 110/14 = 55/7
Thank you,
MrB