Answer:
The total costs will be the same at the 5-month
Step-by-step explanation:
The question is
After how many months will the cost be the same?
Let
x ---> the number of months
y ---> the total charge
we know that
The linear equation in slope intercept form is equal to
[tex]y=mx+b[/tex]
where
m is the slope
b is the y-intercept
Nextel
we have
The slope is equal to
[tex]m=\$50\ per\ month[/tex]
The y-intercept is equal to
[tex]b=\$125[/tex]
substitute
[tex]y=50x+125[/tex] ---> equation A
AT&T
we have
The slope is equal to
[tex]m=\$60\ per\ month[/tex]
The y-intercept is equal to
[tex]b=\$75[/tex]
substitute
[tex]y=60x+75[/tex] ---> equation B
Solve the system of equations by graphing
Remember that the solution of the system is the intersection point both graphs
using a graphing tool
The solution is the point (5,375)
see the attached figure
therefore
The total costs will be the same at the 5-month
Prior to 5 months, Nextel is more expensive.
After 5 months, AT&T is more expensive
