k = -3
Step-by-step explanation:
Let's rewrite the equations in their slope-intercept forms:
[tex]y = \frac{1}{3}x + 2\:\:\:\:\:\:\:(1)[/tex]
[tex]y = kx + 12\:\:\:\:\:(2)[/tex]
In order for Eqn(2) to be perpendicular to Eqn(1), the slope of Eqn(2) must be the negative reciprocal of that of Eqn(1). Therefore, [tex]k = -3[/tex].
