Michele had $55 after 2 weeks of saving money. She plans to have $105 after 7 weeks of saving.which equation matches this scenario?

y - 55 = 10 (x - 2)
y = 7x + 55
10x + 7y = 55
y + 7 = 10 (x + 2)

1 answer

To analyze the scenario, we need to determine the relationship between the weeks of saving and the amount of money Michele has saved.

  1. After 2 weeks (x = 2), Michele has $55 (y = 55).
  2. After 7 weeks (x = 7), Michele plans to have $105 (y = 105).

We can now find the slope (rate of saving) and create the equation of the line.

First, we calculate the change in amount over the change in weeks:

  • From week 2 to week 7 (a change of 5 weeks):
    • From $55 to $105 (a change of $50).

The rate of saving per week is: \[ \text{Rate} = \frac{\Delta y}{\Delta x} = \frac{105 - 55}{7 - 2} = \frac{50}{5} = 10 \text{ dollars per week}. \]

So, Michele saves $10 each week.

Given that she had $55 after 2 weeks, we can set up the equation: \[ y - 55 = 10(x - 2) \] This reflects the scenario correctly.

Now, let's look at the choices:

  • y - 55 = 10 (x - 2) is our derived equation.
  • y = 7x + 55 does not fit our scenario.
  • 10x + 7y = 55 does not fit our linear growth with time.
  • y + 7 = 10(x + 2) does not match the context of the data.

The correct equation that matches the scenario is: \[ \boxed{y - 55 = 10 (x - 2)}. \]