I'm doing test corrections rn but I need to show the work for this answer. The problem is that the this doesn't show the work and I need it for full credit, can someone show me the work please?

The two angles are corresponding angles, so they are congruent (due to the horizontal lines being parallel)
x+15 = 102
x+15-15 = 102-15 .... subtract 15 from both sides
x = 87