Question #e8c24

2 Answers
Apr 12, 2017

Your bill will be 24.63 USD

Explanation:

Since you have a fixed rate for a month (which is 15.99 USD) and time dependent variable, your equation will be:

#15.99+(0.18*time)# If you talk total 48 minutes in a month:

#=15.99+(0.18*48)#
#=15.99+8.64#
#=24.63# USD

Apr 12, 2017

#$24.63#

Explanation:

We can write an equation based on the information in the problem.

#y=mx+b# is the skeleton for our equation.

We can think of #b# as our starting point, the very least we can be charged. The problem tells us our base fee is #$15.99# and that they add on #$.18# for every additional minute.

So #b# is #15.99#, and #m# is our rate, which is #.18#. Now w just need to figure out where that #48# goes. It can either be the #x# or the #y#.

In math, #x# is the independent variable and #y# is the dependent variable. Those might sound like big, science-y words, but they basically mean that a change is #y# is cause by #x#. In this case, the more minutes are use, the money the phone is charged.

So minutes change money. That means #x# is minutes and #y# is money.

#48# is the number of minutes spent talking,s o we're solving for #y# or money:

#y=15.99+48(.18)#
#y=15.99+8.64#
#y=24.63# or #$24.63#