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Write an equation of the line that passes through (8,1) and is perpendicular to the line 2y+4x=12.

y=

User Hjd
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1 Answer

4 votes

First isolate the "y" in the given equation.

2y + 4x = 12 Subtract 4x on both sides

2y = 12 - 4x Divide 2 on both sides

y = 6 - 2x


You will be using the equation:

y = mx + b

"m" is the slope, "b" is the y-intercept (the y value when x = 0)


For lines to be perpendicular, they have to have opposite slopes (flipped sign and number)

For example:

slope is 2

perpendicular line's slope is -1/2(negative)

slope is -4/5

perpendicular line's slope is 5/4(positive)

slope is 1/2

perpendicular line's slope is -2(negative)


The given line's slope is -2, so the perpendicular line's slope is 1/2.

y = mx + b

y = 1/2x + b

To find "b", you plug in the point (8,1) into the equation


y = 1/2x + b

1 = 1/2(8) + b

1 = 4 + b

-3 = b



y = (1)/(2)x-3

User Feathercrown
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