SOLUTION: I am completely lost on this problem can you please explain?
A sales person observes that if an item is priced at $6 per item then 4 items are sold. If it is priced at $8 per it
Question 126141: I am completely lost on this problem can you please explain?
A sales person observes that if an item is priced at $6 per item then 4 items are sold. If it is priced at $8 per item, 2 items are sold. Find an equation to model the number y of items sold for x dollars per item. Answer by marcsam823(57) (Show Source):
You can put this solution on YOUR website! The primary goal of this problem is to find the equation of a line. This is expressed as y = mx + b, where m is the slope of the line and b is the y-intercept (where the line crosses the y axis).
If we remove the "disguises" of dollars and number of items we are simply left with two x-coordinates and two y-coordinates as shown in the chart below:
x | y
_____
6 | 4
8 | 2
1. To find the slope of this line:
m = = = = -1
Using y = mx + b:
y = -1x + b
2. Substitute for x and y (plug in either of the two points - we'll use (6,4)):
y = mx + b
4 = -1(6) + b
3. Find the y-intercept by solving for b:
4 = -6 + b
b = 10
The equation is:
y = -x + 10
Check:
Point (6,4)
4 = -(6) + 10
4 = 4
Point (8,2)
2 = -(8) + 10
2 = 2
(