Write the slope-intercept form of the equation of the line described. - Explain and Show Work

Question

Through: (-1, -1), perpendicular to y = -1/5x + 4

Answer 1

Line  y = -1/5x + 4    has slope (-1/5).  Perpendicular line has slope 5 (negative reciprocal).

Perpendicular line is:   y = 5x + b    and point (-1,-1) needed to find b.

     -1 = 5(-1) + b

      4 = b

Perpendicular line is:   y = 5x + 4

 

Check:  Is (-1)=5(-1)+4  ?  yes, point (-1,-1) is on the perpendicular line.

Answer 2

Crissel, in order to be perpendicular, the new line has to have the opposite, reciprocal slope as the given line, 5 in this case.

 

(y - y₁) = m(x - x₁)

(y - (-1)) = 5(x - (-1)

y + 1 = 5x + 5

      y = 5x + 4

 

Hope this helps!