I'd start with setting up the equations. Calling x the number of students in most popular country 1, and y in country 2.
x + y = 44740
x - y = 5672
now solve for x1 and x2. You can subtract second from first:
0 + 2y = 39068
y = 19534
so
x = 5672 + 19534 = 25206
Add a sentence to answer it in words.
You did it right. 1.35 + 7.00 and you have the right answer. is that what you mean?
So first you would divide 1950/6 to find the amount for one year of their age.
Then you would multiply that by the ages, which should get you 4 numbers, then you all those numbers together. Try 9750.
For this case we have the following function:

By definition, we have that a linear equation is of the form 
On the other hand, a quadratic equation is of the form
Then, the given equation is not a linear equation, it is not of the form 
Answer:
No, the equation is not linear. It is not of the form 