Answer:-5
Step-by-step explanation:
You need to distribute on both sides so u get
9c-15=20-2c
Move variable to left side and change the sign
-9c+2c-15=20
Move constant to right side and change the sign
-9c+2c=20+15
Connect like terms
-7c=35
Divide
C=-5
Question number 10 is the same as the previous questions add them up and make them equal to 180 degrees, and then solve for the x variable.
For the second part of the question, simply plug in the value of x for each expression for R and S.
Answer:

Step-by-step explanation:
First, you make fourteen a fraction.

Then, make it a mixed fraction by adding a six.

Lastly, have a great day! :)