find the value of x (URGENT/GIVING BRAINLIEST)

Answer:
B)10
Step-by-step explanation:
Because this is a right angle(indicated by the red box) the total measure should be 90°.
And based on that we say 5X +40=90
Subtract 40 from both sides to get 5x=50
And then divide both sides by 5 to get x=10
Answer:
x = 10°
Step-by-step explanation:
5x° + 40° = 90°
5x° = 90°-40°
5x°=50°
x°= 50°/5
x = 10°