math
posted by David .
Giselle spent a total of $43 when she went shopping. She spent $14 for socks, $18.75 for a wallet, and bought lunch. When she got home, she had $4 left. How much did she spend for lunch?

Solve for x.
14 + 18.75 + x + 4 = 43
36.75 + x = 43
x = 43  36.75
x = ? 
Why do you add the $4? My daughter missed this on a homework sheet because she didn't use the $4. Why should that even be considered?

We're trying to find out how much she spent for lunch. We can account for the rest of the money.
Another way to work this problem is:
14 + 18.75 + x = 43  4
You'll get the same answer. 
Thanks, but that still makes no sense.
If she SPENT a TOTAL of $43 which included $14 for socks and $18.75 for a wallet and had $4 LEFT, Why does the $4 even have to be in the equation?
$43= $14 + $18.75 + LUNCH (X) 
I see your point. The question states that she SPENT $43. I suggest you have your daughter ask her teacher.

The $4 only enters the picture if asked ,
"how much money did she start with"
it said,
14 + 18.75 + lunch = 43
lunch = 43  14  18.75 = 10.25
So her lunch cost $10.25
She started with 43+4 or $47