After a weekend at the beach, lisa has $274 less than she had when she left. the equation that represents this situation is e=s−274, where e represents the amount of money lisa had at the end of the weekend and s represents the amount of money lisa started with before the weekend.

if lisa started the weekend with $500, how much money did she have at the end of the weekend?

Well that's easy it basically tells you all you gotta do is plug in the numbers 

"E" is what you're trying to find out so you don't know that one it stays the same. 

"S" is the amount of money she started with and it says she started with $500 

And then she has $274 less than she started with. 

E = 500 - 274 

E= 226

She is left with $226 after her weekend at the beach. 

~Hope it helped~