Answer: c = 54
Explanation:
c/6 = 9
you then multiply c/6 by it's denominator, which in this case 6. What you do on one side, you have to do to the other.
6 · c/6 = 9 · 6
Then you multiply everything, 6 cancels out denominator 6 which leaves C and 9 turns into 54. Meaning c equals 54.
c = 54
To check, you can replace c with 54 in your original equation.
54/6
54÷6 = 9