Given:
Steven charges $31.25 for 5 hours and $43.75 for 7 hours.
To find:
The equation that represents the relationship.
Solution:
Let x represent the number of hours Steven babysits and y represent the amount he charges.
Then the two points on the function are (5,31.25) and (7,43.75). So, the equation of the line that passes through these two points is:
[tex]y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)[/tex]
[tex]y-31.25=\dfrac{43.75-31.25}{7-5}(x-5)[/tex]
[tex]y-31.25=\dfrac{12.5}{2}(x-5)[/tex]
[tex]y-31.25=6.25(x-5)[/tex]
On further simplification, we get
[tex]y-31.25=6.25(x)-6.25(5)[/tex]
[tex]y-31.25=6.25x-31.25[/tex]
[tex]y=6.25x-31.25+31.25[/tex]
[tex]y=6.25x[/tex]
Therefore, the required equation for the given situation is [tex]y=6.25x[/tex].