To solve m:
1. Subtract 0.50 in both sides of the equation (subtraction property of equality):
[tex]\begin{gathered} 45.00-0.50=0.50-0.50+0.05m \\ 44.5=0.05m \end{gathered}[/tex]2. Divide both sides of the equation into 0.05 (Division property of equality):
[tex]\begin{gathered} \frac{44.5}{0.05}=\frac{0.05}{0.05}m \\ \\ 890=m \end{gathered}[/tex]3. Rewrite the equation (Symmetric property):
[tex]m=890[/tex]Then, you can use 890 minutes on your $45.00 phone card.