If m∠F = (6x-9)° and m∠G = (2x+13)°, find the value of x such that ∠F and ∠G are supplementary.

(6x-9)°+ (2x+13)° = 90°
8x - 4° = 90°
8x = 86°
x = 10.75

Kaila solved the problem, as shown. Is her solution correct? If it is, explain your reasoning. If not, explain Kaila's mistake and correct the work.