Question 492513
7x + 4 + 4x + 9 = 90 degrees.
11x + 13 = 90 degrees.
11x = 77 degrees.
x = 7
7(7) + 4 = 53 degrees.
4(7) + 9 = 37 degrees.
53 + 37 = 90 degrees. This does check.
Cleomenius.