Answer: x= 115°
Step-by-step explanation: All right triangles equal 180°, so all you have to do is add 40° and 25° (40°+25°= 65°) then subtract the sum (65°) from 180°. The equation would look like this: 180°-65°=115°. The equation to prove this would be 115°+65°=180°.
Hope this helps