Write an equation perpendicular to x – 4y = 20 that passes through the point (2, -5).

Answer 1

Hi Jacasiah G.

x – 4y = 20 

Put the line above in Slope Intercept Form

You can do that by solving for y

y = (1/4)x - 5

The slope, m above is 1/4

The perpendicular will a negative inverse slope m = -4

In Slope Intercept Form your perpendicular line starts below

y = -4x + b

Use the coordinates of the given point on the line (2, -5) to insert and solve for b

-5 = -4(2) + b

-5 = - 8 + b

Add 8 to both sides of the equation

-5 + 8 = b

3 = b

Finally your perpendicular line

y = -4x + 3

I hope this helps

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