Question

Select the correct answer. Which equation represents the line that is perpendicular to y = + and passes through (-40,20)?

Answer 1

For 2 lines to be perpendicular the product of there slope is equals to negative one . Therefore,

`\begin{gathered} m_1m_2=-1 \\ m_1=(4)/(5) \\ m_2*(4)/(5)=-1 \\ m_2=-(5)/(4) \\ \end{gathered}`

The equation can be gotten as follows

`\begin{gathered} m=(y-y_1)/(x-x_1) \\ m=(y-20)/(x+40) \\ m(x+40)=y-20 \\ -(5)/(4)(x+40)=y-20 \\ -(5)/(4)x-(200)/(4)=y-20 \\ -(5)/(4)x-50+20=y \\ y=-(5)/(4)x-30 \end{gathered}`

The answer is B.