Answer:

Step-by-step explanation:
Let
x ----> the number of minutes
y ----> the total charge in dollars
we know that
For x>700 min

so
For y=48.10
substitute

Multiply by 100 both sides
----> equation without decimals
solve for x

To find out the total minutes we need to sum

Is this the image? If so, sorry I can't do this lol