Write an equation for a line parallel to f(x)=-5x-3 and passing through the point (2, -12).

Question

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Answer 1

Parallel lines have the same slope.  Since the equation is already in slope-intercept form, the parallel line is:

       f(x) = -5x-b   [from y=mx+b]  and we need point (2,-12) to determine b.

     -12 = -5(2) -b

       b = 12 -10

        b=2

The equation for the parallel line is:   f(x) = -5x -2

Answer 2

The line y = -5x-3 has slope -5

 

Since parallel lines have the same slope, an equation of the desired line is:

 

     y - (-12) = -5(x-2)

 

     y + 12 = -5x + 10

 

            y = -5x - 2