the angles are complementary because they add up to 90° because of the red square. x=20
Step-by-step explanation:
4x-5+15=90
4x+10=90 subtract 10 from each side
then you get left with 4x=80
divide 4 from each side then you get left with x=20 and to check just substitute 20 where x is so 4(20)-5= 80-5=75 +15=90.
