Answer:

Step-by-step explanation:
If two angles are supplentary, their sum is equal to 180º
If two angles are complementary, their sum is equal to 90º
We know:

Also,

Now, we can write:
![\operatorname{\angle}1+\operatorname{\angle}2=180\Rightarrow(8x+3)+(5x-18)=180]()
And solve for x:

Now we can find the measure of angle 2:

And since angle 2 and 3 are complementary:

And solve:
