Question

You want to know the number of minutes that you can use on your $45.00 phone card. The card company chargesyou $0.50 for the first minute and $0.05 for cach additional minute. Solve the formula $45.00 = $0.50 + $0.05mfor m. Justify each step with an algebraic property of equality.

Answer 1

B 85 cents to the dollar

Answer 2

`45.00=0.50+0.05m`

To solve m:

1. Subtract 0.50 in both sides of the equation (subtraction property of equality):

`\begin{gathered} 45.00-0.50=0.50-0.50+0.05m \\ 44.5=0.05m \end{gathered}`

2. Divide both sides of the equation into 0.05 (Division property of equality):

`\begin{gathered} (44.5)/(0.05)=(0.05)/(0.05)m \\ \\ 890=m \end{gathered}`

3. Rewrite the equation (Symmetric property):

`m=890`Then, you can use 890 minutes on your $45.00 phone card.