we know that
in a right triangle
if sin A= cos B
then
angle A and angle B are complementary angles
so A+B=90
therefore
(2x-8)+(6x-6)=90-------> 8x-14=90----> 8x=104--------> x=13°
(2x-8)-----> 2*13-8----> 18°
(6x-6)-----> 6*13-6----> 72°
if α < β
then
α =18°
β=72°