All GED Math Resources
Example Questions
Example Question #14 : Solving By Factoring
Solve for :
and
and
and
and
For quadratic equations, you need to factor in order to solve for your variable. You do this after the equation is set equal to zero. Thus, you get:
Next do your factoring. You know that both groups will be negative. This will give you a positive last factor but a negative middle term. Given the value of the middle term, the factors of needed will be and
Then, you set each factor equal to . Solve each "small" equation:
or
or
BOTH of these are answers to the equation.
Example Question #11 : Solving By Factoring
Solve for :
This is a quadratic equation, so first, move all terms to the same side by subtracting :
The quadratic polynomial can be factored using the (or grouping) method. We want to split the middle term by finding two integers with sum and product ; through some trial and error, we find and . The equation becomes
Regroup:
Distribute out common factors as follows:
Since the product of these two binomial expressions is equal to 0, one of them is equal to 0; set both to 0 and solve:
Subtract 1 from both sides:
Divide both sides by 3:
or
Add 3 to both sides:
The solution set of the equation is .
Example Question #15 : Solving By Factoring
If , what could be the value of ?
Start by rearranging the given equation:
Next, factor the equation.
Finally, set each factor equal to zero and solve.
and
Since can equal to either , we know that must then equal to either .
Example Question #16 : Solving By Factoring
Solve for .
Start by factoring the equation.
For this equation, you want two numbers that multiply up to and add to . The only numbers that fit this criterion are and .
Thus,
Now, set each of these factors equal to zero and solve.
Example Question #21 : Quadratic Equations
What is the value of if is a positive integer?
Start by factoring the equation.
We will need two numbers that multiply up to and add up to . These two numbers are .
Thus, we can factor the equation.
Solving the equation will give the following solutions:
and
Since the question states that must be a positive integer, can only equal to .
Example Question #22 : Quadratic Equations
. Solve for .
In order to solve this equation, you need to factor the expression,
.
To do so, you need to find two factors of that have a sum of .
The two factors are and and the correct factoring is
,
so you know that
.
Therefore, will be equal to any values that give the inside of the parentheses a value of .
So, is equal to both and .
Example Question #23 : Quadratic Equations
Solve for :
Start by factoring the equation:
For this equation, we will want two numbers that add up to and multiply up to . In this case, the two numbers are and .
We can then write the following:
Now, set each factor equal to zero and solve for .
and
Example Question #21 : Quadratic Equations
For what value of will the following equation be true?
Start by factoring . Since one factor is already given to you, you just need to figure out what number when multiplied by will give and when added to will give . The only number that fits both criteria is . must be equal to .
Example Question #24 : Quadratic Equations
Solve by factoring
or
Not enough information
or
or
or
We must start by factoring
We must think of two numbers that multiply to be 15 and add to be 8. We come up with 3 and 5
Then
So we have
Which means either or
So, or
Example Question #22 : Quadratic Equations
Solve for x by factoring:
or
Looking at , we notice that it is a perfect square trinomial.
*A perfect square trinomial is given by the form (where "a" represents a variable term and "b" represents a constant term).
*Comparing this to our trinomial, we find...
*So, we confirm it is, indeed, a perfect square trinomial.
We have one solution: