Peter received 10 points on a 10 - question quiz. if he received 5 points for each correct answer and lost 3 points for each wrong or missing answer, how many questions did peter answer correctly?

We can use elimination for this question.
There are two equations you need in order to do the process of elimination. The two we’re using is for the points, and the total amount of questions.
C will be for correct and F will be for Incorrect questions (couldn’t use L because it looked close to 1)
5c-3f=10
C+F=10
We need to eliminate one of the variables. Let’s eliminate c by multiplying the second equation by -5.
5c-3f=10
-5c-5f=-50
Now, let’s solve.
-3f-5f= -3+-5
-8f=-40
-40/-8=5
5=f
Since there were five incorrect ones, there are 5 correct ones. Let’s see if we’re right.
5•5 - 5•3
25-15
10
Peter answered 5 correct questions.