Geometry question, please help!!

Answer:
67
Step-by-step explanation:
Any four sided shape has 360 in total angles
You have two right angles=180
so your remaining angles also equal 180 because 360-180=180
set the equation: 15x+8+10x-3=180
add like terms: 15x+10x=25x 8-3=5 25x+5=180
move the five tot he other side to isolate the x: 25x=180-5 25x=175
divide 175 by 25 to get x by itself: x=175/25 x=7
plug in x: 10x-3 10(7)-3 70-3 67
the angle required = 67 degrees