Question 1141072
marie is going to the camera shop to get 10 pictures reprinted. prints that measure 4 inches by 6 inches cost $.50 each, and prints that measure 5 inches by 7 cost $.75 each. if marie has $7 to spend, what is the greatest amount of 5-by-7 prints she can receive?

PLEASE HELP I HAVE NO IDEA WHAT IM DOING
<pre>Let the number of "5 by 7" reprints be L
Then number of "4 by 6" reprints = 10 - L
Cost of "5 by 7" reprints: .75L
Cost of "4 by 6" reprints: .5(10 - L)
We then get: .75L + .5(10 - L) = 7
.75L + 5 - .5L = 7
.25L = 2
L, or number of "5 by 7" reprints = {{{highlight_green(matrix(1,3, 2/.25, "=", 8))}}} <b><===== That's the LARGEST number, if she MUST get "4 by 6" also</b>
You can do the check!