SOLUTION: Find a real number, n, such that the line containing the points (-5, 5) and (-1, 9) contains the point (n, 5).

Algebra ->  Linear-equations -> SOLUTION: Find a real number, n, such that the line containing the points (-5, 5) and (-1, 9) contains the point (n, 5).       Log On


   

Question 362321: Find a real number, n, such that the line containing the points (-5, 5) and (-1, 9) contains the point (n, 5).
Found 2 solutions by robertb, stanbon:
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
%289-5%29%2F%28-1--5%29+=+%285-9%29%2F%28n--1%29,
4%2F4+=+-4%2F%28n%2B1%29,
1+=+-4%2F%28n%2B1%29,
n%2B1+=+-4,
n = -5.
On 2nd thought the value of n should have been clear just by inspection (how?)

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Find a real number, n, such that the line containing
the points (-5, 5) and (-1, 9)
---
slope = (9-5)/(-1--5) = 4/4 = 1
----
Form: y = mx + b
5 = 1(-5)+b
b = 10
Equation of line thru (-5,5) and (-1,9):
y = x + 10
------
contains the point (n, 5).
Substitute n for x and 5 for y; then solve for "n":
5 = n + 10
n = -5
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Cheers,
Stan H.
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