# Find the equation of a line that goes through point (100,-25) and is perpendicular to y=-25?

##### 2 Answers

#### Explanation:

#y=-25#

#"is a horizontal line parallel to the x-axis and passing"#

#"through all points in the plane with a y-coordinate "-25#

#"a line perpendicular to it must be a vertical line"#

#"the equation of such a line is "x=c#

#"where c is the value of the x-coordinate the line"#

#"passes through"#

#"here the point is "(color(red)(100),-25)#

#"the equation of the perpendicular line is "x=100#

#### Explanation:

Recall the standard equation of a line is;

Also recall;

When its perpendicular;

For the first equation;

Coordinate,

Plugging in the value;

Now the new equation of a line is;

Plugging in the values;

Cross multiplying;

Collecting like terms;