Question

Kim bought $100 worth of stock and gained $25 per year. Ari bought $400 worth of stock and lost $35 per year. Use x for time and y for stock value. Graph the equations that represent each situation. The first one is done for you.

Answer 1

1. Kim's case:
We know for our problem that she will gain $25 each year, so if
`x` represents the number of years, she will gain
`25x`, where
`x` is the number of years. We also know that her initial investment is $100. If we let
`y` represent the stock value after
`x` years, we can relate the quantities with the following equation:

`y=25x+100`

We can conclude that the first image is the graph of the equation that represent Kim's situation.

2. Ari's case:
In this case, he is losing $35 per year. Let
`x` represent the number of years. Since we know that losses are represented with a minus sign, he will lose -35x per year. Now, we know for our problem that her initial investment is $400. If we let
`y` represent the stock value after
`x` years, we can relate the quantities with the following equation:

`y=-35x+400`

We can conclude that the second image is the graph of the equation that represent Ari's situation.