Answers:
Adam cannot buy Pair A
Adam cannot buy Pair B
Adam can buy Pair C
Adam can buy Pair D
Adam cannot buy Pair E
Step-by-step explanation:
To know if Adam can buy a pair of shoes, we need to calculate the cost of each pair after the sales tax. If the cost exceeds $70, then Adam cannot buy them.
So, to calculate the cost after the sales tax, we need to calculate 6% of the initial cost. Then, for pair A, we get:

Therefore, the cost after the sales tax is:

Since 73.087 is greater than 70, Adam cannot buy pair A.
In the same way, we can calculate the cost after sales taxes for pair B as:

Therefore, Adam cannot buy pair B.
The cost after sales taxes for pair C is:

Therefore, Adam can buy pair C.
The cost after sales taxes for pair D is:

Therefore, Adam can buy pair D.
The cost after sales taxes for pair E is:

Therefore, Adam can buy pair E.