All Pre-Algebra Resources
Example Questions
Example Question #2 : Graphing Lines
What is the y-intercept of the line ?
In the slope-intercept form of a line, , the y-intercept is when the line intersects the y-axis.
It does this at .
So we plug in for in our equation
to give us
Anything multiplied by is so
Our coordinates for the y-intercept are .
Example Question #4 : Graphing Lines
What is the slope of a line that is parallel to ?
Parallel lines have the same slope.
If an equation is in slope-intercept form, , we take the from our equation and set it equal to the slope of our parallel line.
In this case .
The slope of our parallel line is .
Example Question #3 : Graphing Lines
What is the slope of the line that contains the points, and ?
To find the slope of a line with two points you must properly plug the points into the slope equation for two points which looks like
We must then properly assign the points to the equation as and .
In this case we will make our and our .
Plugging the points into the equation yields
Perform the math to arrive at
The answer is .
Example Question #5 : Graphing Lines
What is the slope of the line that contains the points, and ?
To find the slope of a line with two points you must properly plug the points into the slope equation for two points which looks like
We must then properly assign the points to the equation as and .
In this case we will make our , and our .
Plugging the points into the equation yields
Perform the math to arrive at
The answer is .
Example Question #41 : Graphing
What is the slope of a line that is perpendicular to ?
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 #42 : Graphing
What is the slope of the following line:
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 #43 : Graphing
and are two points on a line. What is the slope of this line?
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 #44 : Graphing
What is the slope of a line containing the points and ?
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 #45 : Graphing
What is the slope-intercept form of a line?
The slope-intercept form of a line is .
Example Question #46 : Graphing
Which of the follow lines is parallel to:
Cannot be determined
It is known that parallel lines have the same slope and therefore a line that is parallel to:
MUST have the same slope of .
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