Answer:
The equation needed is [tex]\textrm{Cost of 1 ream of paper} = \frac{20}{5} [/tex]
The cost per ream of paper = $4
Step-by-step explanation:
Here, the cost of 5 reams of paper = $ 21
The tax on her purchase = $1
So, the actual cost of 5 reams of paper = Total Cost paid - Tax amount
= $ 21 - $ 1 = $20
So, the actual cost of 5 reams of the paper is $20.
Now, to find out the cost of 1 ream of paper:
[tex]\textrm{Cost of 1 ream of paper} = \frac{\textrm{Total amount paid for 5 reams}}{\textrm{ 5}} \\= \frac{20}{5} = 4[/tex]
= $4
Hence, the cost of each ream of paper = $ 4.