Answer
a. $y=12,000x+3000$
b. $8.083$ years
Work Step by Step
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.
