Question

Jarred sells DVDs. His inventory shows that he has a total of 3,500 DVDs. He has 2,342 more contemporary titles than classic titles. Let x represent the number of contemporary titles and y represent the number of classic titles. The system of equations models the given information for both types of DVDs.
x + y = 3,500

x – y = 2,342

Solve the system of equations. How many contemporary titles does Jarred have?

Answer 1

Here, x - y = 2342
x = 2342 + y

Substitute this value into first equation, 
2342 + y + y = 3500
2y = 3500 - 2342
y = 1158/2
y = 579

So, x = 2342 + 579 = 2921

In short, Your Answer would be 2921 contemporary titles

Hope this helps!

Answer 2

Well, if x + y = 3500, we can subtract y from both sides to give us x = 3500 - y. We can substitute that into the second equation:
x - y = 2342
(3500-y) -y = 2342
3500 - 2y = 2342
-2y = 2342-3500 = -1158
2y = 1158
y = 579
And substitute y back into the first equation:
x + y = 3500
x + 579 = 3500
x = 3500-579= 2921

So he has 2,921 contemporary titles. You can substituted the values back into the original equations to check them. Make sense?