So we know that an average is the sum of the scores divided by the number of scores that were added together. In this case we are going to be dealing with 4 tests. So let's say x is the score for our fourth test. We can create this equation:

So then we need to simplify the top:

Then multiply by 4 on both sides to get rid of the denominator:

Then solve for x:

So now we know that Sam needs to score a 67 on the fourth test to have an average score of 50.
Step-by-step explanation:
There can be a lot of math expressions that may equal 13. Here are some of the expressions that equal 13.
Now, let us consider some interesting expression

If the value of x = 2, then the expression will be equal to 13.
i.e.
∵ when x = 2
Considering a word problem
<em>'Tom has 10 oranges while Tony has 3 more oranges than Tom. How many oranges Tony has?</em>
Let 'x' be the number of oranges Tom has.
The number of oranges Tony has = x + 3
as Tom has 10 oranges, so x = 10
Therefore, the number of oranges Tony has = x + 3
= 10 + 3 = 13
Therefore, the number of oranges Tony has = 13
Answer:

Step-by-step explanation:



Answer:
1, 3, 6, 10, 15, 21, 28, 36. Notice that the first 2 terms are odd, followed by another 2 even terms, and then another 2 odd terms, before 2 even terms again.