.
The solution by @ewatrrr is INCORRECT. She READ the problem incorrectly -
THERFORE, her first equation is incorrect, producing errors to the very end.
I came to bring you the correct solution.
Solution
Let x be the angle measure in degrees.
Then the supplement is (180-x); one-fifth of the supplement is and
the complement is (90-x) degrees.
THEREFORE, your equation is
= 2*(90-x) - 9
Multiply both sides by 5 and simplify
180 - x = 10*(90-x) - 45
180 - x = 900 - 10x - 45
10x - x = 900 - 45 - 180
9x = 675
x = 675/9 = 75.
ANSWER. The angle is 75 degrees.
CHECK. Supplement is 105 degrees. One-fifth of supplement is 105/5 = 21 degrees; complement is 15 degrees
and twice the complement is 30 degrees. Finally, 21 degrees is 9 degrees less than 30 degrees. ! Correct !
Solved.
==============
To learn about supplementary / complementary angles, read the lessons
- Angles basics
- HOW TO solve problems on supplementary, complementary or vertical angles - Examples
in this site.
Consider these lessons as your handbook, textbook, guide, tutorials and (free of charge) home teacher.
. . . . . . . .
@ewatrrr fixed her post after seeing my solution.