Answer:
[tex]L(t) = 170 - 10t[/tex]
Step-by-step explanation:
The amount that Alexa owes after t weeks is given by a linear equation in the following format:
[tex]L(t) = L(0) - bt[/tex]
In which L(0) is the initial amount borrowed and b is how much is paid per week.
Alexa agreed to pay back her friend $10 per week and originally borrowed $170.
This means that, respectivelly, [tex]b = 10, L(0) = 170[/tex]. So
[tex]L(t) = L(0) - bt[/tex]
[tex]L(t) = 170 - 10t[/tex]
