Question

If < D and < C are supplementary, and < D = 2x + 2 degrees, and < C = 3x + 18 degrees, find x.

Answer 1

Answer: x = 32

Explanation:

Two angles are supplementary when they are added up to give 180 degrees.

So,

< D + < C = 180°

2x + 2 + 3x + 18 = 180°

5x + 20 = 180°

5x = 180 - 20

5x = 160°

x = 32°

Answer 2

x=32

Explanation:

Because the angles are supplementary then that means when they are added together they equal 180.

What you want to do is add both ∠D and ∠C together so that you have an equation looking like 2x+2+3x+18=180. Next you want to add up all like terms to then get 5x+20=180. Afterwards you need to subtract 20 on both sides to get 5x=160, Lastly, isolate x by dividing by 5 on both sides which will leave you with the equation x=32.