The only ways i thought of was 0.7, 0.70, and 0.700 .
Answer:

Step-by-step explanation:
Using the law if indices
×
= 
Thus to simplify the expression add the 3 exponents
a(b + c) + b(c - a) + c(a - b) ← distribute parenthesis
= ab + ac + bc - ab + ac - bc ← collect like terms
= 2ac
Then the expression simplifies to

Answer:
13% per pair of shoes
because if she 78% on 6 shoes you would divide 78 by 6 to find the percent she spent on one pair of shoes