Answer:
x=6
Step-by-step explanation:
The sum of the angles is a right angle, which is 90 degrees
5x+ x+54 = 90
Combine like terms
6x+54 = 90
Subtract 54 from each side
6x+54-54 = 90-54
6x = 36
Divide each side by 6
6x/6 = 36/6
x= 6
