# Thread: PROBLEM solving(complementary and supplementary) guys help!!

1. ## PROBLEM solving(complementary and supplementary) guys help!!

this is all about the complementary and supplementary angle..
These are the problems I can't solve.. Can anyone explain how to solve this? Advance thanks..

18. If the measure of an angle is (7x-13)degrees and the measure of it's supplement is (5x-11)degrees, find x.

19. Find the measure of the smaller angle of complementary angles, if the measure of the larger angle is (5x+18)degrees and the measure of the smaller angle is half of the larger.

21. Two complementary angles have the difference of 18degrees. Find their measures.

2. First of all, what is your problem exactly? 2 angles a,b are supplementary angles if a+b=180 degrees. And a,b are complementary if a+b= 90 degrees.
Thus it boils down to basic algebra...

18. solve (7x-13)+(5x-11)= 180 for x

19. Solve (5x+18)+1/2(5x+18)= 90 for x and then find the value (5x+18) by plugging in x

20 .....you can do this one.

3. So the answer in 19 must be a fraction number?

4. So the answer in 19 must be a fraction number?
Why not trying to solve the question first, before asking. Yes, x is a fraction number, but (5x+18) is not!