# How many minutes can you talk if you use a $5 phone card to call a friend and the call is$.50 for the first minute and $.15 for each additional minute (or part of a minute)? ##### 1 Answer May 27, 2018 You can talk for $30$minutes. #### Explanation: First, let's list out what we know: We have a $5 phone card.

The first call is $0.50. Every minute after that is $0.15.

Now, let's let $m$ be the number of minutes you can talk.

We know that the minutes times the dollar amount must equal to $5$, and that $0.50 is a constant (no matter how many minutes you call $0.50 is still there.

Since we don't know how many minutes there are but we know the cost for every minute after, that becomes $0.15 m$.

Set the equation:
$0.50 + 0.15 m = 5$

Now solve for $m$. Subtract $\textcolor{b l u e}{0.50}$ from both sides of the equation:
$0.50 + 0.15 m \quad \textcolor{b l u e}{- \quad 0.50} = 5 \quad \textcolor{b l u e}{- \quad 0.50}$

$0.15 m = 4.5$

Then divide both sides by $\textcolor{b l u e}{0.15}$:
$\frac{0.15 m}{\textcolor{b l u e}{0.15}} = \frac{4.5}{\textcolor{b l u e}{0.15}}$

Therefore,
$m = 30$.

You can talk for $30$ minutes.

Hope this helps!