The comeplement of 99

1. the complement is when two angles add up to 99 degrees and the supplement is when the two angles add up to 180 degrees.

2. Let x be the measure of the unknown angle.

3. Let 90 - x be it's complement and 180 - x be the supplement of the angle.

4. Given 90-x=3x+9 the measure of the complement of an angle is 3x+9. Solve using the following steps.

99-x=3x+9

Add x-9 to both sides to isolate x-terms on right side and numbers on left

90-x+x-9=3x+9+x-9

90-x+x-9=3x+9+x-9

91=4x

divide by 4 to both sides yields

91/4=x

5. Given 3x+99=180-x. The measure of the supplement of an angle is 3x+99. So

3x+99=180-x

Add x+99 to both sides of equations to isolate x on right side and number on left

3x+99+x-99=180-x+x-99

4x=91

X=91/4

6. The angle is x=91/4