(10x - 65) degrees is equal to (9x - 49) degrees, therefore you can set them into an equation.
(10x - 65) = (9x - 49)
By subtracting 9x in both sides,
(10x - 9x) - 65 = (9x -9x) - 49
x - 65 = -49
By adding 65 in both sides,
x - 65 + 65= -49 + 65
x = 16
Next, to find the value of z, it’s important to know that the straight line has 180 degrees. Then you would substitute the x value you found into one of your equation and subtract it from 180.
10 (16) - 65 = 160 - 65 = 95
Now you know that (10x - 65) degrees is equal to 95 degrees,
180 - 95 = z = 85
Answer: x = 16
z = 85