SOLUTION: What is the slope of a line that is perpendicular to the line that passes through the points (4,7) and (9,3)? A. -4/5 B. -5/4 C. 4/5 D. 5/4

Algebra ->  Points-lines-and-rays -> SOLUTION: What is the slope of a line that is perpendicular to the line that passes through the points (4,7) and (9,3)? A. -4/5 B. -5/4 C. 4/5 D. 5/4       Log On


   

Question 150781: What is the slope of a line that is perpendicular to the line that passes through the points (4,7) and (9,3)?
A. -4/5 B. -5/4 C. 4/5 D. 5/4
Found 2 solutions by Fombitz, ankor@dixie-net.com:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
First find the slope of the line that passes through those two points.
The formula for slope is,
m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29
m=%283-7%29%2F%289-4%29
m=-%284%2F5%29
Perpendicular lines have slopes that are negative reciprocals of each other.
m%5B1%5Dm%5B2%5D=-1
-%284%2F5%29m%5B2%5D=-1
m%5B2%5D=5%2F4
D) 5/4

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
What is the slope of a line that is perpendicular to the line that passes through the points (4,7) and (9,3)?
:
Use the slope formula to find the slope: m = %28%28y2-y1%29%29%2F%28%28x2-x1%29%29
:
Assign values: x1=4, y1=7; x2=9, y2=3
m1 = %28%283-7%29%29%2F%28%289-4%29%29 = %28-4%29%2F5 = -4%2F5
:
The relationship of slopes of perpendicular lines: m1*m2 = -1; find m2
-4%2F5 * m2 = -1
m2 = -1 * -5%2F4
m2 = +5%2F4 slope of the perpendicular line