Which system of equations can be used to solve for the time it will take for Rafiki's savings to equal the remainder of the loan? (Remember that the loan will be paid off by [tex]$\$ 75$[/tex] each month.)

Let [tex]$x$[/tex] be the number of months, and let [tex]$y$[/tex] be the dollar value of each account.

[tex]\[
\begin{array}{l}
y = 100x + 200 \\
y = 2,000 - 25x
\end{array}
\][/tex]

[tex]\[
\begin{array}{l}
y = 200x + 100 \\
y = 2,000 - 200x
\end{array}
\][/tex]

[tex]\[
y = 100x + 200
\][/tex]

[tex]\[
y = 2,000 - 75x
\][/tex]

[tex]\[
\begin{array}{l}
y = 100x + 200 \\
y = 2,300 - 75x
\end{array}
\][/tex]



Answer :

Let's analyze the different systems of equations to determine which can be used to find when Rafiki's savings will equal the remainder of the loan.

### Understanding the Variables
- [tex]\( x \)[/tex] represents the number of months.
- [tex]\( y \)[/tex] represents the dollar value of each account.

### Systems of Equations

1. System 1:
[tex]\[ \begin{array}{l} y = 100x + 200 \\ y = 2,000 - 25x \end{array} \][/tex]

2. System 2:
[tex]\[ \begin{array}{l} y = 200x + 100 \\ y = 2,000 - 200x \end{array} \][/tex]

3. System 3:

[tex]\[ y = 100x + 200 \\ y = 2,000 - 75x \][/tex]

4. System 4:
[tex]\[ \begin{array}{l} y = 100x + 200 \\ y = 2,300 - 75x \end{array} \][/tex]

### Analyzing Each System

System 1 Analysis:
- Equation 1: [tex]\( y = 100x + 200 \)[/tex]
This can represent savings accumulating from a base of [tex]$200 at a rate of $[/tex]100 per month.
- Equation 2: [tex]\( y = 2,000 - 25x \)[/tex]
This looks like a loan balance starting at [tex]$2,000 and decreasing by $[/tex]25 each month. However, Rafiki's loan is paid off at [tex]$75 each month, not $[/tex]25.

System 2 Analysis:
- Equation 1: [tex]\( y = 200x + 100 \)[/tex]
This suggests savings accumulating, but the rate and base don't seem to match likely scenarios.
- Equation 2: [tex]\( y = 2,000 - 200x \)[/tex]
This decreases too quickly ([tex]$200 per month) compared to the given loan repayable at $[/tex]75 per month.

System 3 Analysis:
- Equation 1: [tex]\( y = 100x + 200 \)[/tex]
This suggests savings start from [tex]$200 and increase by $[/tex]100 every month.
- Equation 2: [tex]\( y = 2,000 - 75x \)[/tex]
This equation indicates the loan starts at [tex]$2,000 and decreases by $[/tex]75 each month, matching the given payment structure.

System 4 Analysis:
- Equation 1: [tex]\( y = 100x + 200 \)[/tex]
This setup matches the savings structure.
- Equation 2: [tex]\( y = 2,300 - 75x \)[/tex]
This indicates the loan balance starts at [tex]$2,300 and decreases by $[/tex]75 each month, which doesn't match $2,000 as the initial loan amount.

### Conclusion
The correct system of equations that can be used to solve for the time it will take for Rafiki's savings to equal the remainder of the loan is:

[tex]\[ y = 100x + 200 \\ y = 2,000 - 75x \][/tex]