Problema Solution

Cell phone world charges a flat rate for unlimited minutes plus a fee per text message. For the month of January, Tobin sent 280 text messages and his total bill was $43.99. For the month of February Tobin sent 490 text messages and his total bill was $54.49. What is cell phone world charging per text message sent?

Answer provided by our tutors

let a be fixed charge and x per message charge

a+280x=43.99

a+490x=54.49

subtracting we get

210x=10.5

x =0.05

so per text cahrrge is %0.05 or 5 cents per message