A trader bought some paraffin for $500.He paid $x for each litre of paraffin.
Qn:
a)Due to a leak,he lost 3 litres of paraffin.He sold the remainder of the paraffin for $1 per litre more than he paid for it.Write down an expression,in terms of x,for the sum of money he received.
b)He made a profit of $20.Write an equation in x to represent this information.

Please do not double-post. This just causes confusion and wastes time, because it's already been answered here:
https://www.askmehelpdesk.com/mathematics/quadratic-equation-involving-money-446416.html

You can't now. Only a mod with that power can get rid of the thread.