Select the equation of the line that passes through the point (5, 7) and is perpendicular to the line x = 4.
a. y=4
b. x=5
c. y=7
d. x=7

Since there are infinite possible answers we will just make our way through the given answers. 

A: Imagine the line for the equation Y=4, it is a straight horizontal line going through every value of x but only one value of Y because it doesn't get any higher or lower. So Y=4 can not be the answer because Y never = 7.

B: Do the same thing and imagine this line. It is a vertical line on the point of X = 5. This one does cross though (5,7) but it is not perpendicular to X= 4 so is not the answer.

C: Crosses through (5,7) and is perpendicular to x = 4. correct answer.