A cell phone company charges a flat rate of $2.50 per month with an additional charge of $.15 per minute. How many minutes did Laura talk on her cell phone if her monthly bill was $72.25
Let's use the formula to calculate Laura's monthly bill:
Total cost = Flat rate + (Additional charge per minute x Number of minutes)
Given that the flat rate is $2.50 and the additional charge per minute is $0.15, we can set up the equation:
$72.25 = $2.50 + $0.15x
Subtracting $2.50 from both sides, we get:
$69.75 = $0.15x
Now, divide both sides by $0.15 to solve for x:
x = $69.75 / $0.15
x = 465
Laura talked for 465 minutes on her cell phone.