Answer: [tex]y=20-1.25x[/tex]
Step-by-step explanation:
The equation of the line in Slope-Intercept form is:
[tex]y=mx+b[/tex]
Where "m" is the slope of the line and "b" is the y-intercept.
You need to analize the information given in the exercise.
You know that gift card had a total of $20. Then, since she started to buy the songs with $20, you can identify that:
[tex]b=20[/tex]
Since Renata purchased 16 songs and the gift card had a remaining balance of $0 after this, you can find the cost of each song. This is:
[tex]\frac{20}{16}=\$1.25[/tex]
Therefore, she spent $1.25 per song. This means that the slope is:
[tex]m=-1.25[/tex]
Then, you get that the equation that represents the relationship between "y" (the remaining balance on Renata's gift card) and "x" (the number of songs purchased) is:
[tex]y=20-1.25x[/tex]
