html and math....

[cherylrae7]

I need to create with html a math sequence where people are inputting data. I've got all of it worked out so far except the end where the output is then multiplied by 5%.

I can't seem to get it right. Can someone please take a look? I know I am missing the final integer. but I've tried several things.

<form oninput="x.value=parseInt(a.value)*parseInt(b.value)-*parseInt(c.value)">
<input type="number" id="a">
x<input type="number" id="b" >
-<input type="number" id="c" >
=<output name="x" for="a b c"></output>
</form>

ok so the actual string on the page looks like this:

how many students in the class? : ________input a______* how much is the class?: _____input b_____ - expenses____input c_____

the final output needs to be a number that shows them 5% of the total so they'll know what to send to paypal.

Any help is sooooo appreciated! thank you in advance!