You can put this solution on YOUR website!
You need to use more parentheses when you render an expression in plain text. I'm not clear on whether you mean:
or
There are other possible interpretations but these seem most likely.
The first one rearranges to:
The second rearranges to:
Whichever it is, just substitute your given values and do the indicated arithmetic.
John
My calculator said it, I believe it, that settles it