Answer:
C
Step-by-step explanation:
First, factor the original expression:
As we can see, D is the same as above. Eliminate D.
Go through each of the answer choices.
A:
This is equivalent to what we factored. Eliminate A.
B:
This is again equivalent to what we factored. Eliminate B.
C:
This cannot be simplified and it is not equivalent to what we have previously. C is not the equivalent expression.
Answer:
C
Step-by-step explanation:
When completing the square, we essentially want to create a perfect square trinomial by adding a constant.
If we have the following expression:
And we want to complete the square, we will need to divide the b-coefficient by half and then square it.
Thus, the added term should be:
In the given equation, we have:
The b term here is 8. Therefore:
The value we would add would be 16.
The answer is C.
Further notes:
To complete the square, add 16 like mentioned earlier. However, we also need to subtract 16 to balance things out:
The expression inside the parentheses is now a perfect square trinomial. Factor it:
And we are done!
Answer:
He received 10 dimes and 15 quarters.
Step-by-step explanation:
Dimes = $0.10
Quarters = $0.25
Variable x = dimes
Variable y = quarters
Create a pair of linear equations:
0.10x + 0.25y = 4.75
x + y = 25
Isolate any variable, using an equation of your choice:
x + y = 25
x = 25 - y
Plug in this new value of x into the other equation:
0.10(25 - y) + 0.25y = 4.75
Use the distributive property:
2.5 - 0.10y + 0.25y = 4.75
Combine like terms:
2.5 + 0.15y = 4.75
Isolate variable y:
0.15y = 2.25
y = 15
Plug in the value of y into any equation:
x + y = 25
x + 15 = 25
Isolate variable x:
x = 10
Answer:
B) (2x + 3)(2x - 3)
Step-by-step explanation:
Use the FOIL method for each answer choice.
FOIL = First, Outside, Inside, Last
(2x)(2x) = 4x²
(2x)(-3) = -6x
(3)(2x) = 6x
(3)(-3) = -9
4x² -6x +6x -9
Simplify. Combine like terms:
4x² (-6x + 6x) - 9
4x² - 9
4x² - 9 = 4x² - 9 ∴ B) (2x + 3)(2x - 3) is your answer
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