Trigonometry (10th Edition)

69$^{\circ}$ and 21$^{\circ}$
9x + 6 + 3x = 90$^{\circ}$ 12x + 6 = 90$^{\circ}$ 12x = 84$^{\circ}$ x = 7$^{\circ}$ therefore 9x + 6 = 69$^{\circ}$ and 3x = 21$^{\circ}$