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Line p is perpendicular to the line y=1/4x-3 and passes through (-8,2). line m is the image of line p Dilated centered at the origin with scale factor of 2/5. What is the equation of line m?

1 Answer

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Step-by-step explanation:

First we have to find the equation of line p, which is perpendicular to y=1/4x - 3, therefore its slope is reciprocal and opposite to the given line:


y_p=-4x+b

To find the y-intercept b we have to use the point. Replace x = -8, y = 2 and solve for b:


\begin{gathered} 2=-4(-8)+b \\ 2=32+b \\ b=2-32 \\ b=-30 \end{gathered}

The equation of line p is:


y_p=-4x-30

Now, line m is a dialation of line p centered at the origin, so the slope doesn't change - this means that line m is parallel to line p - and the y-intercept is the product of the y-intercept of line p by the scale factor:


\begin{gathered} y_m=-4x-30\cdot(2)/(5) \\ y_m=-4x-12 \end{gathered}

Answer:

The equation of line m is y = -4x - 12

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