[tex]\text{First, find the common denominator for the fractions}\\\\-\frac{5}{8}+(-\frac{8}{5})\\\\\text{We know that they both can multiple to 40, 8 times 5; 5 times 8}\\\\\text{The multiplying you're doing in the bottom, you will do the same for}\\\text{the top}\\\\\text{Your expression should look like this:}\\\\-\frac{25}{40}+(-\frac{64}{40})\\\\\text{Add across}\\\\\boxed{-\frac{89}{40}}\\\\\text{You can't simplify it any further, so that would be the simplest form}\\\text{in a improper fraction}[/tex]
[tex]\text{In you need it as a mixed number, your answer would be:}\\\\\boxed{-2\frac{9}{40}}[/tex]
