Explanation
We are to set up the equations for plans A and B
If the number of minutes is m
For plan A, we will have
The cost C will be
[tex]C=0.06m[/tex]
For plan B
the cost will be
[tex]C=3.6+0.05m[/tex]
We are asked to find the amount of monthly phone price for which plan A will exceed B
[tex]0.06m\ge3.6+0.05m[/tex]
Solving for m
[tex]\begin{gathered} 0.06m-0.05m>3.6 \\ \\ 0.01m>3.6 \\ \\ m>\frac{3.6}{0.01} \\ \\ m>360 \end{gathered}[/tex]
This means that for all amounts greater than 360 minutes, plan A will cost more than B
[tex]m>360\text{ minutes}[/tex]
