For this case, the first thing we must do is define variables.
We have then:
x: number of minutes
y: total cost
We write the algebraic expression that models the problem.
We have then:
[tex] y = 10 * (\frac{20}{60}) x
[/tex]
Simplifying we have:
[tex] y = (\frac{10}{3}) x
[/tex]
Then, by the time the cost is equal to $ 300 we have:
[tex] 300 = (\frac{10}{3}) x
[/tex]
From here, we clear the value of x.
Answer:
an algebraic expression for the problem is:
[tex] 300 = (\frac{10}{3}) x [/tex]
