Answer: 5 sheets
Explanation:
The question seems incomplete, however, I found the mentioned equation:
[tex]C=40 (5-s)[/tex]
We are told [tex]C[/tex] is in units of [tex]\$[/tex] and [tex]s[/tex] is in units of [tex]sheets[/tex], this means the other side of the equation must be in [tex]\$[/tex], as well.
So, if we make a dimensional analysis :
[tex]\$=40\frac{\$}{sheets} (sheets)[/tex]
This means each sheet costs [tex]\$40[/tex], then with a Rule of three, we can find how many sheets Hiro can purchase with [tex]\$200[/tex]:
If:
1 sheet ---- [tex]\$40[/tex]
s sheets ---- [tex]\$200[/tex]
Then:
[tex]s=\frac{(\$200)(1 sheet)}{\$40}=5 sheets[/tex]
Therefore, [tex]C=\$0[/tex] (the total credit left is zero) and we can verify [tex]s=5[/tex] by isolating it from the equation:
[tex]s=\frac{200 - C}{40}[/tex]
[tex]s=\frac{200 - 0}{40}[/tex]
[tex]s=5[/tex]
