SOLUTION: if point A, having coordinates (9,p) and point B, have coordinates (p,7), lie on a line having slope of -1/3, what is the value of p?

Algebra ->  Graphs -> SOLUTION: if point A, having coordinates (9,p) and point B, have coordinates (p,7), lie on a line having slope of -1/3, what is the value of p?      Log On


   

Question 1140108: if point A, having coordinates (9,p) and point B, have coordinates (p,7), lie on a line having slope of -1/3, what is the value of p?
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
given:
point A=(9,p)
point B=(p,7)
m=+-1%2F3
use slope formula:
m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29.......plug in coordinates of given points
-1%2F3=%287-p%29%2F%28p-9%29...........solve or p
-1%28p-9%29=3%287-p%29
-1p%2B9=21-3p
3p-1p=21-9
2p=12
p=6
point A=(9,6)
point B=(6,7)
now, if you want to check solution, use slope point formula to find equation of that line
y-y%5B1%5D=m%28x-x%5B1%5D%29.......plug in slope and one point
y-6=-%281%2F3%29%28x-9%29
y-6=-%281%2F3%29x%2B3
y=-%281%2F3%29x%2B3%2B6
y=-%281%2F3%29x%2B9
check the solution on a graph: