How do I add fractions with a variable and without a variable on the other one. For example in below

Question

anonymous · Answer

$$\frac{ 7c+2d }{ 8c } - \frac{ c+2d }{ 2c } + 3$$

ddcamp · Answer

When adding fractions, you find a common denominator.
What could you multiply the top and bottom of the second fraction by so that it has the same denominator as the first fraction?

anonymous · Answer

4, but then what would I do with the 3? It'd end u being $$\frac{ 3c-6d }{ 8c } + 3$$

ddcamp · Answer

For the three, multiply it by (8c/8c) to get
$$\frac{ 3c-6d }{ 8c }-\frac{ 8c }{ 8c }3 = \frac{ 3c-6d }{ 8c }- \frac{ 24c }{ 8c }$$

anonymous · Answer

So the answer is $$\frac{ 21c-6d }{ 8c }$$  ?

anonymous · Answer

then it would be 13c-6d?

ddcamp · Answer

Sorry, it's supposed to be +(24c/8c)

The final answer should be (27c - 6d)/8c