High School

A number, [tex]n[/tex], is added to 15 less than 3 times itself. The result is 101. Which equation can be used to find the value of [tex]n[/tex]?

A. [tex]3n - 15 + n = 101[/tex]
B. [tex]3n + 15 + n = 101[/tex]
C. [tex]3n - 15 - n = 101[/tex]
D. [tex]3n + 15 - n = 101[/tex]

Answer :

Sure! Let's solve the problem step-by-step.

Given:
- A number, [tex]\( n \)[/tex], is added to 15 less than 3 times itself.
- The result is 101.

We need to find the equation that helps to determine the value of [tex]\( n \)[/tex].

### Step-by-Step Solution

1. Understanding the Problem:

- We have a number [tex]\( n \)[/tex].
- We need to add this number [tex]\( n \)[/tex] to another expression which is:
[tex]\[
15 \text{ less than 3 times } n
\][/tex]
- The sum is equal to 101.

2. Forming the Expression:

- "3 times [tex]\( n \)[/tex]" can be written as:
[tex]\[
3n
\][/tex]
- "15 less than 3 times [tex]\( n \)[/tex]" means we subtract 15 from [tex]\( 3n \)[/tex]:
[tex]\[
3n - 15
\][/tex]
- Now, we add [tex]\( n \)[/tex] to this expression:
[tex]\[
n + (3n - 15)
\][/tex]

3. Writing the Equation:

- According to the problem, the above sum is equal to 101. So we set up the equation:
[tex]\[
n + (3n - 15) = 101
\][/tex]

4. Simplifying the Equation:

- Combine like terms:
[tex]\[
n + 3n - 15 = 101
\][/tex]
[tex]\[
4n - 15 = 101
\][/tex]

5. Solving for [tex]\( n \)[/tex]:

- Add 15 to both sides of the equation to isolate the term with [tex]\( n \)[/tex]:
[tex]\[
4n - 15 + 15 = 101 + 15
\][/tex]
[tex]\[
4n = 116
\][/tex]

- Now, divide both sides by 4:
[tex]\[
n = \frac{116}{4}
\][/tex]
[tex]\[
n = 29
\][/tex]

6. Conclusion:

- Therefore, the equation that can be used to find the value of [tex]\( n \)[/tex] is:
[tex]\[
3n - 15 + n = 101
\][/tex]

The correct equation from the given options is:
[tex]\[
3n - 15 + n = 101
\][/tex]

So, the equation is:
[tex]\[
3n - 15 + n = 101
\][/tex]
And the value of [tex]\( n \)[/tex] is:
[tex]\[
n = 29
\][/tex]