Hey! I'll provide the steps below on solving this.
First, reduce the numbers with the greatest common divisor, which is 2.
[tex]c - \frac{3}{10} = 3 ( \frac{9}{5})[/tex]
Then, calculate the products on the right side.
[tex]c - \frac{3}{10} = \frac{27}{5} [/tex]
Now move the constant to the right side and change its sign.
[tex]c = \frac{27}{5} + \frac{3}{10} [/tex]
Finally, multiply the first fraction up to LCF and add the fractions.
[tex]c = \frac{57}{10} [/tex]