Answer: 42
Step-by-step explanation:
Ok what you want to do is add all of them up and equal it to 180 because a triangle is 180 degrees .
Your equation should look like this
9x-3+22x+1+42-3x = 180
What you want to do first is combine all the x and numbers on the left side so it should look like this
1) 28x+40= 180
Then you want to subtract 40 on both sides so it will look like this
2)28x=140
You want to get x by it self so you divide 28 on both sides
3) x=140/28
4) x=5
Since you are finding c you have to insert 5 into x
1) 9(5)-3
2)45-3
Then your answer should be 42