Question

Choose the equation of the line passing through the point (4, -2) and perpendicular to y =1/3 x - 7.

y = -3x - 14

y = 3x - 10

y = -3x + 10

y = 3x + 14

Answer 1

The gradient of the given line is 1/3. Let the gradient of the required line be m. Then
\[m*\frac{1}{3}=-1\]
from this m can be found.
\[gradient~m=\frac{y-y_1}{x-x_1}\]
\[m(x-x_1)=y-y_1\]
\[y=m(x-x_1)+y_1\]
\[y=mx-mx_1+y_1\]
Here
\(x_1=4~and~y_1=-2\)
Does that help? @manueld167