All High School Math Resources
Example Questions
Example Question #1 : How To Find The Equation Of A Circle
The center of a circle is and its radius is
. Which of the following could be the equation of the circle?
The general equation of a circle is , where the center of the circle is
and the radius is
.
Thus, we plug the values given into the above equation to get .
Example Question #1 : How To Find The Equation Of A Circle
Which one of these equations accurately describes a circle with a center of and a radius of
?
The standard formula for a circle is , with
the center of the circle and
the radius.
Plug in our given information.
This describes what we are looking for. This equation is not one of the answer choices, however, so subtract from both sides.
Example Question #1 : Equations
Tom is painting a fence feet long. He starts at the West end of the fence and paints at a rate of
feet per hour. After
hours, Huck joins Tom and begins painting from the East end of the fence at a rate of
feet per hour. After
hours of the two boys painting at the same time, Tom leaves Huck to finish the job by himself.
If Huck completes painting the entire fence after Tom leaves, how many more hours will Huck work than Tom?
Tom paints for a total of hours (2 on his own, 2 with Huck's help). Since he paints at a rate of
feet per hour, use the formula
(or
)
to determine the total length of the fence Tom paints.
feet
Subtracting this from the total length of the fence feet gives the length of the fence Tom will NOT paint:
feet. If Huck finishes the job, he will paint that
feet of the fence. Using
, we can determine how long this will take Huck to do:
hours.
If Huck works hours and Tom works
hours, he works
more hours than Tom.
Example Question #1 : Equations
Simplify the fraction to the lowest terms:
Cannot be simplified
Find the common multiple between the numerator and denominator.
divide numerator and denominator by 3:
divide numerator and denominator by 7:
divide numerator and denominator by 4:
Cannot be divided any more- lowest terms.
Example Question #1 : Equations
Solve the following equation for x in terms of the other variables:
Multiply both sides by to get:
Distribute the :
Combine like terms:
Divide both sides by :
Example Question #2 : Equations
Solve the following equation for x in terms of the other variables:
Divide both sides by :
Example Question #1 : Equations
If given the equation , with
a positive integer, the result must be an integer multiple of:
10
12
8
5
2
5
The mathematical expression given in the question is . Adding together like terms,
, this can be simplified to
. The expression
can be factored as
. For every positive integer
,
must be a multiple of 5. If
, then
, which is not an integer multiple of 2, 8, 10, or 15. Therefore, the correct answer is 5.
Example Question #1 : Equations
Cindy's Cotton Candy sells cotton candy by the bag. Her monthly fixed costs are . It costs
to make each bag and she sells them for
.
What is the monthly break-even point?
The break-even point occurs when the .
The equation to solve becomes
so the break-even point is
.
Example Question #1 : Equations
Cindy's Cotton Candy sells cotton candy by the bag. Her monthly fixed costs are . It costs
to make each bag and she sells them for
.
To make a profit of , how many bags of cotton candy must be sold?
So the equation to solve becomes , or
must be sold to make a profit of
.
Example Question #3 : Equations
Solve for and
to satisfy both equations in the system:
,
,
,
,
,
,
The two equations in this system can be combined by addition or subtraction to solve for and
. Isolate the
variable to solve for it by multiplying the top equation by
so that when the equations are combined the
term disappears.
Divide both sides by to find
as the value for
.
Substituting for
in both of the two equations in the system and solving for
gives a value of
for
.
All High School Math Resources
