## Calculus with Applications (10th Edition)

a. $y=12,000x+3000$ b. $8.083$ years
a. The line (graph) contains points with coordinates (year, sales). Points on the graph (given by the text): (2, 27,000) , (5, 63,000). The slope is: $m=\displaystyle \frac{63,000-27,000}{5-2}=12,000$ Point-slope form of the line equation: $y-27,000=12,000(x-2)$ $y-27,000=12,000x-24, 000\qquad/+27,000$ $y=12,000x+3000$ b. Find x when $y=100,000$: Solve for x: $100, 000=12,000x+3000\qquad/-3000$ $97, 000=12, 000x\qquad /\div 12,000$ $8.083=x$ Sales would surpass \$100,000 after$8.083\$ years.