Given fx)= 10-2x, find f(7) -4 3 7 56
2 answers:
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Answer:
b.
Step-by-step explanation:
We have to look at sign changes in f(x) to determine the possible positive real roots.
There is only one sign change here, between the -8x and the +4. So that means there is only 1 possible real positive root.
Now we have to look at sign changes in f(-x) to determine the possible negative real roots.
There are 3 sign changes here. That means there are either 3 negative roots or 3-2 = 1 negative root. So we have:
1 positive
3 or 1 negative
We need to pair them up now with all the possible combinations.
If we have 1 positive and 1 negative, we have to have 2 imaginary
If we have 1 positive and 3 negative, we have to have 0 imaginary
Keep in mind that the total number or roots--positive, negative, imaginary--have to add up to equal the degree of the polynomial. This is a 4th degree polynomial, so we will have 4 roots.
QUESTION:
Simplify each expression
ANSWER:
1.)
2.)
3.)
4.) for number 4 study my step-by-step explanation so you can answer that
STEP-BY-STEP EXPLANATION:
1.) First, If the term doesn't have a coefficients, it is considered that the coefficients is 1
WHY?
Learn why:
Why is it considered that the coefficient is 1?
Remember that any term multiplied by remains the same :
Step 1:
The equality can be read in the other way as a well, so any term can be written as a product of and itself:
Step 2:
Usually, we don't need to write multiplacation sign between the coefficient and variable, so the simple form is:
This is why we can write the term without the coefficient as a term with coefficient
Now let's go back to solving as what i said if a term doesn't have a coefficient, it is considered that the coefficient is 1
Second, Collect like terms by subtracting their coefficients
Third, Calculate the difference
how?
Keep the sign of the number with the larger absolute value and subtract the smaller absolute value from larger
Subtract the numbers
- ()n
- n
2.) First, Distribute - 6 through the parentheses
how?
Multiply each term in the parentheses by - 6
Multiply the numbers
- -
- -
Second, Collect like term
how?
Collect like terms by calculating the sum or difference of their coefficient
Calculate the sum
b
b
3.) First, Distribute 2 through parentheses
how?
Multiply each term in the parentheses by 2
Multiply the numbers
Second, Distribute - 4 through the parentheses
how?
Multiply each term in the parentheses by - 4
Calculate the product
- x - 4
- x - 4
Third, Collect like terms
how?
Collect like terms by subtracting their coefficient
Calculate the difference
x
x
Fourth, Calculate the difference
how?
Factor out the negative sign from the expression
Add the numbers
- ()
-
That's all I know sorry but I hope it helps :)