PART A:
The generic equation of the line is:
y-yo = m (x-xo)
First we look for the slope of the line:
m = (y2-y1) / (x2-x1)
m = ((5000) - (6000)) / (4-3)
m = -1000
Then, we substitute any point in the generic equation:
(xo, yo) = (4, 5000)
Substituting:
y-5000 = (- 1000) (x-4)
Rewriting:
y = -1000x + 4000 + 5000
y = -1000x + 9000
The equation is:
y = -1000x + 9000
PART B:
For the price of 3.50 we have:
y = -1000 * (3.5) +9000
y = 5500
The equation has three factors and equals zero
One of the factors must be zero.
Either 3x = 0 which means x = 0
or x - 4 = 0 which means x = 4
or 3x + 5 = 0 which means 3x = -5 so x = -5/3
The answer is C
E cannot be correct in this question as you are asked to “solve” and not just pick a correct option
