## Intermediate Algebra (6th Edition)

$3$ gallon-containers
A rectangular room with length$\times$width$\times$height dimensions of $14\times18\times8$ has two walls with dimensions $14\times8$ and two walls with dimensions $18\times8.$ Using $A=lw,$ the total area of these walls is \begin{array}{l}\require{cancel} A_{total}=2A_1+2A_2 \\ A_{total}=2(14)(8)+2(18)(8) \\ A_{total}=224+288 \\ A_{total}=512 .\end{array} Since $2$ coatings will be applied, then a total of $2(512)$ or $1024$ square feet will be painted. With each gallon of latex paint able to cover $400$ square feet, then a total of $3$ gallon-containers is needed.