So a complementary angle is going to equal 90 degrees.
The equation is : x - 10 + 4x - 10 = 90
Then, add together the matching terms : 5x - 20 = 90
Add 20 to both sides : 5x = 110
Then divide both sides by 5 : x = 22
Insert the value 22 into the first equation : (22 - 10) + (4*22 - 10) = 90
Solve : 12 + 78 = 90
Angle UVW = 12 and angle XYZ = 78