SOLUTION: 64x^3+343 x^4+8x^2-9 these are the two polynomials im left with! pleasee help! thankss!

Question 133352: 64x^3+343
x^4+8x^2-9
these are the two polynomials im left with!
pleasee help!
thankss!
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
Do you want to factor?

# 1

Start with the given expression.

Rewrite as . Rewrite as .

Now factor by using the sum of cubes formula. Remember the sum of cubes formula is

Multiply

-----------------------------------
Answer:

So factors to .

In other words,

# 2

Looking at we can see that the first term is and the last term is where the coefficients are 1 and -9 respectively.

Now multiply the first coefficient 1 and the last coefficient -9 to get -9. Now what two numbers multiply to -9 and add to the middle coefficient 8? Let's list all of the factors of -9:

Factors of -9:
1,3

-1,-3 ...List the negative factors as well. This will allow us to find all possible combinations

These factors pair up and multiply to -9
(1)*(-9)
(-1)*(9)

note: remember, the product of a negative and a positive number is a negative number

Now which of these pairs add to 8? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to 8

First Number	Second Number	Sum
1	-9	1+(-9)=-8
-1	9	-1+9=8

From this list we can see that -1 and 9 add up to 8 and multiply to -9

Now looking at the expression , replace with (notice adds up to . So it is equivalent to )

Now let's factor by grouping:

Group like terms

Factor out the GCF of out of the first group. Factor out the GCF of out of the second group

Since we have a common term of , we can combine like terms

So factors to

So this also means that factors to (since is equivalent to )

So factors to

Now factor by using the difference of squares
------------------------------------------------------------

Answer:

So factors to
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