Answer:
The inequality is 
Step-by-step explanation:
Total time:
The total time to complete the test is the sum of the number of multiple-choice questions multiplied by the time it takes to solve each and the number of short-answer questions multiply by the time it takes to solve each.
In this question:
Same number(n) of both.
Multiple-choice takes 2 minutes, short-answer takes 3.5 minutes. The total time is given by:

Write an inequality to determine how many questions, n, the teacher can include if the test must take students less than 45 minutes to complete.?
This means that:

So

The inequality is 
7x+10y=6400
x+y=700
x=700-y
7(700-y)+10y=6400
4900-7y+10y=6400
-7y+10y=1500
3y=1500
y=500
x=700-y
x=700-500
x=200
there were 200 children and 500 adults at the show
So for this, you'll be using the pythagorean theorem, which is
. In this case, 10 and 24 are the legs, and AB is the hypotenuse. Our equation will be 
Firstly, solve the exponents: 
Next, combine 100 and 576: 
And lastly, square root both sides to get 
And in short, Line AB is 26 ft, or the first option.