Answer:
x = 5
Step-by-step explanation:
We have: The sum of the measures of angle M and angle R is 90°
So: M + R = 90° (1)
But M = (5x + 10)°
Plug M into (1)
So: (5x + 10)° + R = 90° (2)
Plug R=55° into (2)
So: (5x + 10)° + 55° = 90°
⇔ 5x + 10 + 55 = 90
⇔ 5x + 65 = 90
⇔ 5x = 25
⇔ x = 5
I hope this answer will help you.