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What is the equation of a line that is perpendicular to y=3x-2 and passes through the point (6 8) ?

A)y=-1/3x+10
B)y=1/3x+6
C)y=-1/3x+4
D)y=-1/3x+8

User Kemin Zhou
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1 Answer

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The result is a line perpendicular to y=3x-2
This line has the following equation: y =mx + b, where m = slope

Remember that the product of the slopes of two perpendicular lines is always = -1 (or in other term one is the reciprocal inverse of the other) so the
first slope = 3 and the sope perpendicular to 3 will be - 1/3.
Then the new equation is y = - 1/3(x) + b
How to calculate b? This line passes through (6, 8), that
means (x=6 and y=8) . Plug these values in y = -1/3 (x)+b:3
8=(-1/3)(6) + b;
8= - 2 + b and b = 10
Te final equation is y = - 1/3.x+10 (answer A)
User Ivan Peric
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