Question

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

Answer 1

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.

Answer 2

If the line is perpendicular to x = 4, then that means the answer should be y = some number

and since we have the equation going through point (5,7), we look at the y-value since our equation is y=some number and replace the y-value into that equation.

So the correct answer is C. y = 7

Hope that helps :)