All Common Core: 8th Grade Math Resources
Example Questions
Example Question #1 : How To Find Slope
A line has the equation
. What is the slope of this line?
You need to put the equation in
form before you can easily find out its slope.
Since
, that must be the slope.Example Question #91 : Expressions & Equations
The equation of a line is
. Find the slope of this line.
To find the slope, you will need to put the equation in
form. The value of will be the slope.
Subtract
from either side:
Divide each side by
:
You can now easily identify the value of
.
Example Question #1 : How To Find X Or Y Intercept
What is the
-intercept of the graph of the function ?
The
-intercept of the graph of a function is the point at which it intersects the -axis - that is, at which . This point is , so evaluate :
The
-intercept is .Example Question #1 : Use Similar Triangles To Show Equal Slopes: Ccss.Math.Content.8.Ee.B.6
Give the
-intercept, if there is one, of the graph of the equation
The graph has no
-intercept.
The graph has no
-intercept.The
-intercept is the point at which the graph crosses the -axis; at this point, the -coordinate is 0, so substitute for in the equation:
However, since this expression has 0 in a denominator, it is of undefined value. This means that there is no value of
paired with -coordinate 0, and, subsequently, the graph of the equation has no -intercept.Example Question #1 : Use Similar Triangles To Show Equal Slopes: Ccss.Math.Content.8.Ee.B.6
Give the
-intercept, if there is one, of the graph of the equation
The graph has no
-intercept.
The
-intercept is the point at which the graph crosses the -axis; at this point, the -coordinate is 0, so substitute for in the equation:
The
-intercept is .Example Question #131 : Grade 8
Give the
-intercept, if there is one, of the graph of the equation.
The graph does not have a
-intercept.
The
-intercept is the point at which the graph crosses the -axis; at this point, the -coordinate is 0, so substitute for in the equation:
The
-intercept is the point .Example Question #132 : Grade 8
A line passes through
and is perpendicular to the line of the equation . Give the -intercept of this line.
The line has no
-intercept.
First, find the slope of the second line
by solving for as follows:
The equation is now in the slope-intercept form
; the slope of the second line is the -coefficient .The first line, being perpendicular to the second, has as its slope the opposite of the reciprocal of
, which is .Therefore, we are looking for a line through
with slope . Using point-slope form
with
,
the equation becomes
.
To find the
-intercept, substitute 0 for and solve for :
The
-intercept is the point .Example Question #4 : Use Similar Triangles To Show Equal Slopes: Ccss.Math.Content.8.Ee.B.6
A line passes through
and is parallel to the line of the equation . Give the -intercept of this line.
The line has no
-intercept.
First, find the slope of the second line
by solving for as follows:
The equation is now in the slope-intercept form
; the slope of the second line is the -coefficient .The first line, being parallel to the second, has the same slope.
Therefore, we are looking for a line through
with slope . Using point-slope form
with
,
the equation becomes
.
To find the
-intercept, substitute 0 for and solve for :
The
-intercept is the point .Example Question #1 : How To Find X Or Y Intercept
Give the
-intercept of the line with slope that passes through point .
The line has no
-intercept.
By the point-slope formula, this line has the equation
where
By substitution, the equation becomes
To find the
-intercept, substitute 0 for and solve for :
The
-intercept is the point .Example Question #6 : Use Similar Triangles To Show Equal Slopes: Ccss.Math.Content.8.Ee.B.6
Give the
-intercept of the line that passes through points and .
The line has no
-intercept.
First, find the slope of the line, using the slope formula
setting
:
By the point-slope formula, this line has the equation
where
; the line becomes
or
To find the
-intercept, substitute 0 for and solve for :
The
-intercept is .
All Common Core: 8th Grade Math Resources
