find sin(-8/17)+(-3/5))

I'm assuming you mean the sin of ((-8/17) + (-3/5)) since you seemed to have a partial set of parentheses. . .

So the sine of the whole thing, inputted into this site's calculator, would be $$\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{sin}}{\left({\mathtt{\,-\,}}\left({\frac{{\mathtt{8}}}{{\mathtt{17}}}}\right){\mathtt{\,-\,}}\left({\frac{{\mathtt{3}}}{{\mathtt{5}}}}\right)\right)} = -{\mathtt{0.018\: \!684\: \!202\: \!361}}$$

On the other hand, if you didn't mean the extra parentheses and meant sin(-8/17) added onto (-3/5) instead, it would be

$$\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{sin}}{\left({\mathtt{\,-\,}}{\frac{{\mathtt{8}}}{{\mathtt{17}}}}\right)}{\mathtt{\,-\,}}\left({\frac{{\mathtt{3}}}{{\mathtt{5}}}}\right) = -{\mathtt{0.608\: \!213\: \!221\: \!784}}$$

I do not believe that this question is what you intended.

It was probably suppose to be an inverse sine question!

I suggest that you check your question and repost it correctly.

I am sure that is not what was meant Kitty but it doesn't matter - You get 3 more points.