Question

Select the equation of the line that passes through the point (5,7) and is perpendicular to the x = 4

Answer 1

y= -1*x +12

Explanation:

x=4 is a function that always has the value 4 for the x-axis, no matter y variable, this a vertical function.

Perpendicular Lines are those with the following condition:

y=a*x+b (1)

y=c*x+d (2)

Where a and c are the respective slope

If These two lines are perpendicular, then

a=- 1/c

Using those principles we have that the slope for our needed line has to be -1, since the slope for the first line is 1 (the coefficient of x is 1, in the line x=4)

Lets use the given point (5,7) in the equation (2)

7=-1 * 5 + d

resulting d=12

so, our equation for the line is y= -1*x +12