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Give the slope intercept form of the equation of the line that is perpendicular to 3x-4y=17 and contains P(6,4)

User Gemantzu
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1 Answer

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For this case we have that by definition, the equation of a line in the slope-intersection form is given by:


y = mx + b

Where:

m: It's the slope

b: It is the cut-off point with the y axis

On the other hand we have that if two lines are perpendicular, then the product of their slopes is -1. So:


m_ {1} * m_ {2} = - 1

The given line is:
3x-4y = 17\\-4y = 17-3x\\4y = 3x-17\\y = \frac {3} {4} x- \frac {17} {4}

So we have:


m = \frac {3} {4}

We find
m_ {2}:


m_ {2} = \frac {-1} {\frac {3} {4}}\\m = - \frac {4} {3}

So, a line perpendicular to the one given is of the form:


y = - \frac {4} {3} x + b

We substitute the given point to find "b":
4 = - \frac {4} {3} (6) + b\\4 = -8 + b\\4 + 8 = b\\b = 12

Finally, the line is:


y = - \frac {4} {3} x + 12

Answer:


y = - \frac {4} {3} x + 12

User Pablo Abdelhay
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