What does perpendicular mean? Well, in elementary geometry it mean 2 lines that intersect at a right angle. (90°).
So for Part one. all you need to do is draw a straight line down from the point X. Name the end point of that line M.
Now you will connect the line M and Z.
Thats it! I hope this helped!! :)
Answer:
The answer is 10
Step-by-step explanation:

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
A. Commutative Property
"The commutative property states that the order in which two numbers are added or multiplied does not affect the sum or product." ~ ck12.org
May I have brainliest please? :)