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Question 431238: which equation represents a line that passes through the points (2,3) and (-1, -3)?
Found 3 solutions by mananth, ikleyn, josgarithmetic:
Answer by mananth(16949)   (Show Source):
You can put this solution on YOUR website! x1 y1 x2 y2
2 3 -1 -3
slope m = (y2-y1)/(x2-x1) 2
m= -3
Plug value of the slope and point (2,3) in y= mx+b
3.00 = -6 + b
b= 3 -6
b= 9
So the equation will be
Y =-3x+ 9
Answer by ikleyn(53419)  (Show Source):
You can put this solution on YOUR website! .
which equation represents a line that passes through the points (2,3) and (-1,-3) ?
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The solution in the post by @mananth is incorrect: it has many arithmetic errors.
I came to bring a correct solution.
Having two points given by their coordinates, we first calculate the slope of the line.
To calculate the slope m, use the formula m =  .
The numerator is y2 - y1 = -3 - 3 = -6.
The denominator is x2 - x1 = -1 - 2 = -3.
So, the slope is m =  = 2.
We look for equation in the form
y = mx + b = 2x + b.
We just know the slope 'm'; so, we only need to find 'b'.
To find 'b', plug coordinates (2,3) in this equation
3 = 2*2 + b
and find b = 3 - 4 = -1.
So the equation of the line is y = 2x - 1. <<<---=== ANSWER
At the end, to be sure, we must check that this equation satisfies coordinates of both points.
I leave this check to you, since it is pure mechanical job.
Solved.
Answer by josgarithmetic(39701)  (Show Source):
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