given m||n, find the value of x

By using the corresponding angles theorem we can see that (6x - 5)° and (x - 25)° are supplementary angles, so they add up to 180°.
This means that:
(6x - 5) + (x - 25) = 180
7x - 30 = 180
7x = 210
x = 30
If you want to find the exact values of the angles, just plug x = 30 into the angle values! :)