Question

Jenelle has 5 gallons of paint after painting 800 ft.² of walls in her house. she has 3 gallons left. the graph below shows Jenelle’s situation.

Answer 1

given the points

(0,5), 0 ft^2of wall painted, 5 gallons of paint left

(800,3), 800 ft^2 of wall painted, 3 gallons of paint left

slope is given by

$m=\frac{y2-y1}{x2-x1}$

then

$m=\frac{3-5}{800-0}$$m=\frac{-2}{800}$$m=-\frac{1}{400}$

the line equation is

$y=mx+b$

where b is the y-intercept = 5

then

$y=-\frac{1}{400}x+5$

then

the correct answer is option A