Ele's car is [tex]$x$[/tex] years old, and Kat's car is [tex]$y$[/tex] years old. Kat's car is 3 times as old as Ele's car. If Kat's car is also 6 years older than Ele's car, which of the following systems of equations best models this situation?

Choose 1 answer:

A. [tex]x = 3y \\
x - y = 6[/tex]

B. [tex]x = 3y \\
y - x = 6[/tex]

C. [tex]y = 3x[/tex]



Answer :

Sure! Let's work through the problem step by step.

We are given two relationships concerning the ages of Ele's car ([tex]\(x\)[/tex] years old) and Kat's car ([tex]\(y\)[/tex] years old):

1. Kat's car is 3 times as old as Ele's car. This can be written as the equation:
[tex]\[ y = 3x \][/tex]

2. Kat's car is also 6 years older than Ele's car. This can be written as the equation:
[tex]\[ y = x + 6 \][/tex]

Now, let's consider the given multiple-choice options:

### Option (A)
[tex]\[ x = 3y \\ x - y = 6 \][/tex]
Analyzing Option (A):
- The equation [tex]\(x = 3y\)[/tex] would imply that Ele's car is 3 times as old as Kat's car, which contradicts the problem statement.
- Therefore, Option (A) is incorrect.

### Option (B)
[tex]\[ x = 3y \\ y - x = 6 \][/tex]
Analyzing Option (B):
- Similar to Option (A), the equation [tex]\(x = 3y\)[/tex] suggests that Ele's car is 3 times as old as Kat's car, which contradicts the problem statement.
- Therefore, Option (B) is incorrect.

### Option (C)
[tex]\[ y = 3x \][/tex]
Analyzing Option (C):
- The equation [tex]\(y = 3x\)[/tex] correctly represents the statement that Kat's car is 3 times as old as Ele's car.
- We also derived [tex]\(y = x + 6\)[/tex], and both conditions are simultaneously met when the equations are considered together.

Let's verify by solving the equations together:
1. [tex]\(y = 3x\)[/tex]
2. [tex]\(y = x + 6\)[/tex]

Since both equations equal [tex]\(y\)[/tex], we can set them equal to each other:
[tex]\[ 3x = x + 6 \][/tex]
Solving for [tex]\(x\)[/tex], we subtract [tex]\(x\)[/tex] from both sides:
[tex]\[ 2x = 6 \][/tex]
Dividing both sides by 2:
[tex]\[ x = 3 \][/tex]

Substituting [tex]\(x = 3\)[/tex] back into [tex]\(y = 3x\)[/tex]:
[tex]\[ y = 3(3) = 9 \][/tex]

So, Ele's car is 3 years old, and Kat's car is 9 years old. The equation [tex]\(y = x + 6\)[/tex] also holds true because [tex]\(9 = 3 + 6\)[/tex].

Therefore, the system of equations that best models the situation is:
[tex]\[ \boxed{y = 3x} \][/tex]

So, the correct answer is (C).