A cell phone plan includes 900 anytime minutes for [tex][tex]$\$[/tex]40[tex]$[/tex] per month, plus a one-time activation fee of [tex]$[/tex]\[tex]$32$[/tex][/tex]. Let [tex][tex]$x$[/tex][/tex] represent the number of months and [tex][tex]$y$[/tex][/tex] represent the cost in dollars. Answer parts (a) through (c).

(a) Write an equation in the form [tex][tex]$y = mx + b$[/tex][/tex] for this situation.

(b) Find and interpret the ordered pair associated with the equation for [tex][tex]$x=7$[/tex][/tex].

(c) Over a two-year contract, how much will this plan cost?



Answer :

Certainly! Let's tackle each part of this question step by step.

### Part (a)

To write an equation in the form [tex]\( y = mx + b \)[/tex] for this cell phone plan, we need to identify what [tex]\( m \)[/tex] and [tex]\( b \)[/tex] represent.

- [tex]\( m \)[/tex] represents the cost per month. Here, the cost is [tex]$40 per month. - \( b \) represents the one-time activation fee. This fee is $[/tex]32.

So, the equation in slope-intercept form [tex]\( y = mx + b \)[/tex] for this situation is:

[tex]\[ y = 40x + 32 \][/tex]

### Part (b)

Next, we need to find and interpret the ordered pair associated with the equation for [tex]\( x = 7 \)[/tex].

- Substitute [tex]\( x = 7 \)[/tex] into the equation [tex]\( y = 40x + 32 \)[/tex]:

[tex]\[ y = 40(7) + 32 \][/tex]
[tex]\[ y = 280 + 32 \][/tex]
[tex]\[ y = 312 \][/tex]

Therefore, the ordered pair is [tex]\( (7, 312) \)[/tex].

Interpretation of the ordered pair: When [tex]\( x = 7 \)[/tex], it represents the cost after 7 months. So, after 7 months, the total cost of the cell phone plan is [tex]$312. ### Part (c) Finally, we calculate the total cost over a two-year contract. Since there are 12 months in a year, a two-year contract means \( 24 \) months. - Substitute \( x = 24 \) into the equation \( y = 40x + 32 \): \[ y = 40(24) + 32 \] \[ y = 960 + 32 \] \[ y = 992 \] Total cost: Over a two-year contract (24 months), the total cost of this plan is $[/tex]992.

To summarize:

(a) The equation is [tex]\( y = 40x + 32 \)[/tex].

(b) The ordered pair for [tex]\( x = 7 \)[/tex] is [tex]\( (7, 312) \)[/tex], which means after 7 months, the total cost is [tex]$312. (c) Over a two-year contract, the cost will be $[/tex]992.