Question

A phone company offers two monthly plans plan A cost $9 Plus And additional 0.12 $ for each minute of calls. Plan B cost $27 plus an additional $0.07 for each minute of calls

Answer 1

Answer: They will charge same amount for 360 minutes of calls.

Step-by-step explanation:

A phone company offers two monthly plans plan A cost $9 Plus And additional 0.12 $ for each minute of calls. Plan B cost $27 plus an additional $0.07 for each minute of calls

For what amount of calling do the two plans cost the same?

Let the each minute of calls be 'x'.

So, for plan A would be

plan A cost $9 Plus And additional 0.12 $ for each minute of calls is expressed as

$y_1=9+0.12x$

Plan B cost $27 plus an additional $0.07 for each minute of calls is expressed as

$y_2=27+0.07x$

According to question, it becomes,

$y_1=y_2\\\\9+0.12x=27+0.07x\\\\0.12x-0.07x=27-9\\\\0.05x=18\\\\x=\dfrac{18}{0.05}\\\\x=360$

Hence, they will charge same amount for 360 minutes of calls.