Laws of exponents:
(a^x)^y=a^(xy)
a^0=1 (a≠0)
Therefore
(7^13)^3.7^0
=(7^(13*3)). 1
=7^39
Mary added
cups of sugar.
<h3>
How to estimate how much sugar should Mary add?</h3>
The ratio of flour to sugar exists at 9 cups: 2 4/7 cups
Utilizing equivalent ratios, given that 7 cups of sugar was utilized,
Let cups of flour needed = x such that our equation becomes
flour/sugar
Convert mixed numbers into improper fractions

simplifying the above equation, we get

= 
x = 24.5
The value of x = 24.5.
Therefore,
cups of sugar exist required.
To learn more about improper fractions refer to:
brainly.com/question/387381
#SPJ9
X = 14
1/2 of 14 = 7
7 + 13 = 20
1/2,3/4,2/3...................