Pre-Algebra : Graphing Lines

Example Questions

Example Question #1133 : High School Math

What is the slope of a line that is perpendicular to ?

Explanation:

The slope of a perpendicular lines has the negative reciprocal of the slope of the original line.

If an equation is in slope-intercept form, , we use the  from our equation as our original slope.

In this case

First flip the sign

To find the reciprocal you take the integer and make it a fraction by placing a  over it. If it is already a fraction just flip the numerator and denominator.

Do this to make the slope

The slope of the perpendicular line is

.

Example Question #11 : Graphing Lines

What is the slope of the following line:

Explanation:

To be able to identify the slope of a line, we need to get it in the form of

.

To do this we need to change the coefficient of y to be  instead of . To do this, divide both sides of the equation by .

Now we can tell what the value of m, or the slope, is:

Example Question #12 : Graphing Lines

and  are two points on a line. What is the slope of this line?

Explanation:

The slope of the line is determined by . In other words, we can use the formula .

Let's choose the coordinate  to be ( , )  and  to be ( , ).

We can now use the formula above:

Example Question #43 : Graphing

What is the slope of a line containing the points  and ?

Explanation:

The formula to calculate slope  between two points in a line is , for points  and

If we pick  as our  and  as our , then:

This simplifies to , which can be reduced to

Example Question #13 : Graphing Lines

What is the slope-intercept form of a line?

Explanation:

The slope-intercept form of a line is .

Example Question #14 : Graphing Lines

Which of the follow lines is parallel to:

Cannot be determined

Explanation:

It is known that parallel lines have the same slope and therefore a line that is parallel to:

MUST have the same slope of .

Example Question #51 : Graphing

Write an equation in point-slope form for a line parallel to the line

that goes through the point:  .

Explanation:

You know that point-slope form is:

and therefore you must look at the slope of your equation given which is .

From there you just plug in what is given:

for ,

for ,

and  for

Example Question #1 : Graphing

A line graphed on the coordinate plane below.

Give the equation of the line in slope intercept form.

Explanation:

The slope of the line is  and the y-intercept is .

The equation of the line is

Example Question #13 : Graphing Lines

What is the slope and y-intercept of the equation

Explanation:

The slope intercept formula is:

Example Question #15 : Graphing Lines

What is the slope and y-intercept of the equation below?

Slope =

Y-intercept =

Slope =

Y-intercept =

Slope =

Y-intercept =

Slope =

Y-intercept =

Slope =

Y-intercept =

Slope =

Y-intercept =

Explanation:

In order to understand this question you must understand what slope intercept form is.

= slope

= y-intercept

The slope is

The y-intercept is