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What is an equation of the line that passes through the point (-1,-6) and is perpendicular to the line X+4y=12

User Fatfatson
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1 Answer

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Explanation:

I think you mean you need the equation in slope-intercept form :

y = ax + b

"a" being the slope, "b" being the y-intercept value (the y-value when x = 0).

the slope is always the ratio of

y coordinate difference / x coordinate difference

when going from one point on the line to another.

a perpendicular slope turns this ratio upside-down and flips the sign :

- x coordinate difference / y coordinate difference

so, first let's bring the given line to a slope-intercept form too to get its parameters :

x + 4y = 12

4y = -x + 12

y = -x/4 + 12/4 = -x/4 + 3

so, the slope of the given line is -1/4.

the perpendicular slope is then - -4/1 = 4.

now we have the slope of the requested line. to get the y-intercept we use the given point :

-6 = 4×-1 + b = -4 + b

-2 = b

so, our full equation is

y = 4x - 2

User Heslacher
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