SOLUTION: Find a if the point (3,a) is on the line that passes through (-2,7) and (5,-3).

Algebra ->  Coordinate-system -> SOLUTION: Find a if the point (3,a) is on the line that passes through (-2,7) and (5,-3).      Log On


   

Question 1068373: Find a if the point (3,a) is on the line that passes through (-2,7) and (5,-3).
Found 2 solutions by Lightning_Fast, josgarithmetic:
Answer by Lightning_Fast(78) About Me  (Show Source):
You can put this solution on YOUR website!
Use point slope form.
Find "m"
Using "m" find "b"
Boom, you have the equation of the line in slope intercept form.
Plug in 3 for x and solve for the y axis, or a.
Alternatively, you can skip to finding the point by using only the point intercept formula.
.

Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
Find the equation for the line.
m=%287-%28-3%29%29%2F%28-2-5%29
m=10%2F%28-7%29
m=-10%2F7
-
y-7=-%2810%2F7%29%28x%2B2%29
y=-10x%2F7-20%2F7%2B7
y=-10x%2F7-20%2F7%2B70%2F7
y=-10x%2F7%2B50%2F7

let x = 3 and find 'a'.
y=-10%2A3%2F7%2B50%2F7
y=-30%2F7%2B50%2F7
y=20%2F7


highlight%28a=20%2F7%29