Solve for x (supplementary angle problem thing)

It's a complimentary angle.

Complimentary angles both add up to 90 degrees, as you can also tell by the square with indicates a 90 degree angle.

Make (x + 54) + 5x = 90.

x + 54 + 5x = 90

Add like terms.

6x + 54 = 90

Subtract the 54.

6x = 36

Divide by 6.

x = 6