Question 1097148
Write an equation of the lines described in problems 39 through 41.

39. with undefined slope, through (-1/8,5)
Undefined slope ---> parallel to the y-axis, often called vertical.
That means x is constant, for all values of y.
--> x = -1/8
============================
40. Through (-1,4), parallel to the y-axis
Same as above.
x = -1
============================
41. perpendicular to y=7, through (9,-7)
y = 7 is parallel to the x-axis.  y=7 for all values of x.
Perpendicular gives parallel to the y-axis, same as the 1st 2
--> x = 9