Jayne stopped to get gas before going on a road trip. The tank already had 4 gallons of gas in it. Which equation relates the total amount of gasoline in the tank, [tex][tex]$y$[/tex][/tex], to the number of gallons that she put in the tank, [tex][tex]$x$[/tex][/tex]?

A. [tex][tex]$y = 4 + x$[/tex][/tex]
B. [tex][tex]$y = x - 4$[/tex][/tex]
C. [tex][tex]$y = 4 \cdot x$[/tex][/tex]
D. [tex][tex]$y = x \div 4$[/tex][/tex]



Answer :

Sure, let's break down the problem step-by-step to find the correct equation that relates the total amount of gasoline in the tank [tex]\( y \)[/tex] to the number of gallons that Jayne added [tex]\( x \)[/tex].

1. Understand what we know:
- Jayne already had 4 gallons of gas in the tank.
- She then adds [tex]\( x \)[/tex] gallons of gas to the tank.

2. Determine the relationship between the total gasoline in the tank and the additional gasoline added:
- The total amount of gasoline [tex]\( y \)[/tex] is the sum of the gasoline already in the tank and the gasoline she added.
- Since the tank already has 4 gallons, we can say [tex]\( y = 4 \)[/tex] (initial gas) [tex]\( + x \)[/tex] (gas added).

3. Translate this relationship into an equation:
- Total gasoline [tex]\( y = 4 + x \)[/tex].

4. Evaluate the given choices:
- [tex]\( y = 4 + x \)[/tex]: This matches our equation perfectly.
- [tex]\( y = x - 4 \)[/tex]: This would mean subtracting 4 gallons from what she added, which doesn't match our situation.
- [tex]\( y = 4 \cdot x \)[/tex]: This suggests the total gasoline is the product of 4 gallons and the added gallons, which is incorrect.
- [tex]\( y = x \div 4 \)[/tex]: This would imply dividing the added gasoline by 4, which is also incorrect.

So, the correct equation that represents the relationship between the total amount of gasoline in the tank [tex]\( y \)[/tex] and the number of gallons [tex]\( x \)[/tex] that Jayne puts in the tank is:

[tex]\[ y = 4 + x \][/tex]

Therefore, the correct answer is:
[tex]\[ \boxed{y = 4 + x} \][/tex]