## Prealgebra (7th Edition)

The cost of the software is \$420. The cost of the computer system is \$1680.
Let the cost of the software be $s$. The cost if the computer system be $4s$. $s+4s=2100$ $\longrightarrow$combine like terms $5s=2100$ $\longrightarrow$multiplication property $5s\div5=2100\div5$ $\longrightarrow$divide $s=420$ $4s=4\times420=1680$