Answer:
y = -1000x +11000
Step-by-step explanation:
<u>Given:</u>
(x, y) = (sales price, number sold) = (3, 8000), (6, 5000)
<u>Find</u>:
slope-intercept equation for a line through these points
<u>Solution</u>:
When given two points, it often works well to start with the 2-point form of the equation for a line.
y = (y2 -y1)/(x2 -x1)(x -x1) +y1
Filling in the given points, you have ...
y = (5000 -8000)/(6 -3)/(x -3) +8000
y = (-3000/3)(x -3) +8000
y = -1000x +3000 +8000 . . . . eliminate parentheses
y = -1000x +11000 . . . . the desired equation