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Question 485683: I need help with how to find missing coordinates!
Find the value of k
(-3,2k)(k,6) m=4
Found 2 solutions by solver91311, Theo:
Answer by solver91311(24713)   (Show Source):
Answer by Theo(13342)  (Show Source):
You can put this solution on YOUR website! if this is supposed to be a straight line, then m is the slope.
the equation of a straight line is equal to:
y = mx + b
m is the slope
b is the y intercept
the slope is given by the equation.
m = (y2-y1)/x2-x1)
the coordinates you are given can be labeled as:
(x1,y1) = (-3,2k)
(x2,y2) = (k,6)
y2 - y1 would be equal to 6 - 2k
x2 - x1 would be equal to k - (-3) which is equal to k + 3
the slope is therefore equal to (6-2k) / (k+3) and is equal to 4.
you need to solve that equation for k.
you have (6-2k) / (k+3) = 4
multiply both sides of this equation by (k+3) to get:
(6-2k) = 4 * (k+3)
simplify to get:
6 - 2k = 4k + 12
subtract 4k from both sides of the equation and subtract 6 from both sides of the equation to get:
-2k - 4k = 12 - 6
simplify to get:
-6k = 6
divide both sides of the equation by -6 to get:
k = -1
when k = -6, your coordinates becomes:
(-3,-2) and (-1,6) with m = 4
(x1,y1) = (-3,-2)
(x2,y1) = (-1,6)
y2 - y1 = 6 - (-2) = 8
x2 - x1 = -1 - (-3) = 2
8/2 = a slope of 4 which confirms the calculations are correct.
your answer is that k = -1
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