Answer:

Step-by-step explanation:
Given equation is
. We require x in terms of c.

Dividing both sides with 3 we get

Add 7 on both sides we get

Dividing both sides with c we get

Answer is in this image which is 72.
Thank you for your question!
Your really close!
Just set this up as an algebraic equation:
4x - 10 = 30
4x = 40
x = 10
Hope this helped!