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Write an equation for a line that passes through (1,-4) and (3,-5)

User Rguy
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1 Answer

12 votes

Answer:

y = -3/4x - 1/2

Explanation:

Given:

Point 1: (1, -4)

Point 2: (3, -5)

Find:

The equation for the line that passes through Point 1 & Point 2

Solution:

y = mx + b

Will be the equation to arrive to at the very end, but we need m & b, the slope and the y-intercept

m = ( y2 - y1 ) / ( x2 - x1 ) = ( -5 - (-4) ) / ( 3 - 1 ) = -1 / 2

∴ m = - 1/2

Using either P1 or P2, plug in one of their respective x- and y-values into:

y = -1/2 x + b

I'll do (3, -5):

-5 = -1/2 ( 3 ) + b

-2 = -3/2 + b

-4 = -3 + 2b

-1 = 2b

∴ b = -1/2

y = -3/4x - 1/2 is the equation of the line that passes thru both points (-5, 4) and (3, -2)

User Bulkan
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