Question

A science test, which is worth 100 points, consists of 24 questions. Each question is worth either 3 points or 5 points. If x is the number of 3-point questions and y is the number of 5-point questions, the system shown represents this situation.
x + y = 24

3x + 5y = 100

Answer 1

First, you would want to know whether if you are using Elimination or Substitution.
Second, it takes a lot of work to explain here, so I'll tell you that y-value is anywhere from 10 to 15 (PS: "anywhere from 10 to 15" is not the actual answer, don't put that on your homework paper).

Hint: (-3x) + (+3x) = 0

Play around with the numbers, it will give you knowledge plus it is kind of fun and your brain is expanding when you get confused. It is okay to get the wrong answer, just try and keep trying. At least try.