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HELP OMG PLS
what equation describes a line that passes through (-1,8) (5,-2)

User Kspacja
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1 Answer

7 votes

1. The first step to answering this question is to find the gradient of the line on which the given points are situated. The formula for the gradient is given by:

m = (y2 - y1) / (x2 - x1), where (x1, y1) and (x2, y2) are two points on the line

Thus, given that we have the two points (-1, 8) and (5, -2), we can substitute these into the equation above to find the gradient:

m = (-2 - 8) / (5 - (-1))

m = -10 / (5 + 1)

m = -10/6

m = -5/3

2. The second step is to find the equation of the line itself. This can be achieved by substituting the gradient and one point into the formula for a straight line below:

y - y1 = m(x - x1), where m is the gradient and (x1, y1) is one point on the line

We can use either of the given points so let's use (-1, 8), and the gradient of -5/3 that we found in step 1:

y - 8 = (-5/3)(x - (-1))

y = (-5/3)(x + 1) + 8 (Add 8 to both sides)

y = (-5/3)x - 5/3 + 8 (Expand (-5/3)(x + 1) )

y = (-5/3)x + 19/3

Thus, the equation that we are looking for is y = (-5/3)x + 19/3

User Aghast
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