# Question #b7c26

Jul 4, 2016

I would say: $y = 0.3 x + 75$

#### Explanation:

Tou can write it as:
$y = 0.3 x + 75$
where $y$ represents the monthly cost considering the $x$ minutes.

Jul 4, 2016

$y = 0.3 x - 225$

#### Explanation:

The first thing is to find out how many minutes there are more than the first 1000 minutes. Find the difference:

Number of minutes in excess of 1000 = $x - 1000$

For each of those minutes he will pay $0.30. He also pays the monthly fee of$75.

The total cost $y$ is:

$y = 75 + 0.3 \left(x - 1000\right)$

This simplifies to $y = 75 + 0.3 x - 300$

$y = 0.3 x - 225$

Check: Assume he uses 1200 minutes
Cost = $75 + 0.3 \times 200 = 135$
or: $y = 0.3 \times 1200 - 225 = 135$