Explanation:
I don't know if this is the right way to so it, but I would do it like this
since a triangle has 180 degrees, the angles all have to add up to 180
So 180 = a + b + c
we already know a, its 95
So 180 = 95 + b + c
now we know the equation for b, so we'll just put it there instead of the b, and since the angles are the same, we should put it instead of c too
180 = 95 + (4x-15) + (4x-15)
now subtract 95 from both sides
85 = (4x-15) + (4x-15)
add the xs and numbers together
85 = 8x - 30
now add the 30 to both sides
115 = 8x
divide by 8
your x is 14 3/8 or 14.375 or 115/8
that's not your angle, that's your x