Answer:
You only have to sort (numbers with numbers and variables with variables) then do the operations (+/-).
Step-by-step explanation:

Paula 34%. 21 divided by 60
Cory 35%. 16 divided by 40
Krista 40%. 17 divided by 50
<h2>
Hello!</h2>
The answer is:
a) Her reasoning is incorrect, she applied a wrong operation, the way to simplify the expression was using the square root property. If we want to extract a number of a square root, we must square that number first in order not to modify the expression.
b) We have that:

and rounding to the nearest tenth, we have that:

<h2>
Why?</h2>
To solve the problem, we need to remember the following property of square roots:

We are given the expression:

We can rewrite it by the following way:

Now, applying the square root property we have:

Therefore,
a) Her reasoning was wrong, she applied a wrong operation, the way to simplify the expression was using the square root property. If we want to extract a number of a square root, we must square that number first in order not to modify the expression.
b) We have that:

and rounding to the nearest tenth, we have that:

Have a nice day!
And the question is ?
wich one is longer?
or wich one is older?
1 yd = 3 ft
area= pi r ^2
area=3.14 • 3^2
area= 3.14 • 9
area= 28.26ft^2
rounded to nearest 10th: 28.3 ft^2
ANSWER: J. 28.3 ft 2