One of the product rules for exponents was used.

Or, you can consider that the definition of an exponent and the associative and commutative properties of multiplication were used.
What is the total cost or it is unsolvable?
Answer:
6.5
Step-by-step explanation:
7 5/8 + 5 3/8= 13
13/2=6.5
as we know that <span>If the 4" side of the card was scaled up to 10.5
then the scaling factor is 10.5/4 = 2.625.
The 5 side would be the length 5 x 2.625 = 13.125 which exceeds the maximum dimension of 11.
Thus, it is the 5 side which is scaled up to 10.5 and the scaling factor is therefore 10.5/5 = 2.1.
The scaled up length of the 4 side is thus 4 x 2.1 = 8.4.</span>