Write the equation of a line that intersects the y axis at the same point as the given line, but is perpendicular to it.

a) [[$ y = – 2x + 7 $]]

Answer: The equation is [[$ y = $]] .

b) [[$ y = x + 12 $]]

Answer: The equation is [[$ y = $]] .

c) [[$ y = \displaystyle\frac {1} {3}x – 5 $]]

Answer: The equation is [[$ y = $]] .

d) [[$ y = –4x $]]

Answer: The equation is [[$ y = $]] .