x=4. If a triangle is equal to 180 and there is a right angle, subtract 90 from 180. You should then take 15x and 8x-2 to form an equation with the 90. So, 15x+8x-2=90 or 23x-2=90. Then add two on both sides and you’ll have 23x=92 and then boom x=4. Sorry that doesn’t make sense.