You can put this solution on YOUR website! The question "what does 5/3w = -10" equal" doesn't make sense. Instead, you would rather say "5/3w = -10, what does w equal?"
Additionally, are you saying
, or
?
If then you can multiply both sides by 3/5, yielding w = -6. Or, if then cross-multiplying, -30w = 5, w = -1/6.