There is no solution is the answer. I had this in one of my math tests so I'm positive it's correct :D
Steps
find the Least Common Multiple of the denominators (which is called the Least Common Denominator).
Change each fraction (using equivalent fractions) to make their denominators the same as the least common denominator.
Then add (or subtract) the fractions, as we wish!
your denominators stay the same so its 20
