Answer:
x = 3.87
Explanation:
We know the unlabelled angle is 90 degrees since it is a right triangle. The sum of the other two angles is 5x^2 +x^2 = 6x^2
the sum of all angles is 90 degrees.
90 + 6x^2 = 180
6x^2 = 90
x^2 = 90/6 = 15
x = square root of 15 which is 3.87