Answer:
C = 125
Explanation:
Since a straight line is 180 degrees. We can conclude that:
10x + 15 + 5x = 180
And that:
C = 10x + 15
First we need to find the value of x to find C. So,
10x + 15 + 5x = 180
15x + 15 = 180
- 15 -15
15x = 165
15x/15 = 165/15
x = 11
So now, we need to substitute the values of x into C and solve it.
C = 10(11) + 15
= 110 + 15
= 125