Math Help for Section 8.1, Page 384

Applications
To model a real-life situation with a system of equations, you can use
the same
basic problem-solving strategy that has been used throughout the text.

After answering the question, remember to check the answer in the
original
statement of the problem.

Example
5: Check
When a bundle of shingles costs \$22 and a roll of roofing paper costs
\$18, the contractor’s first purchase costs

   
$30({\color{red}22})+4({\color{red}18})=660+72=\$732$

and the contractor’s second purchase costs

    $8({\color{red}22})+1({\color{red}18})=176+18=\$194$.

The solution checks. ✓