MHB Factor Polynomial: x^3-27, Find A, B, C

  • Thread starter Thread starter cchacon92
  • Start date Start date
  • Tags Tags
    Polynomial
Click For Summary
The polynomial x^3 - 27 can be factored using the difference of cubes formula. The correct factorization is (x - 3)(x^2 + 3x + 9). In this expression, A equals 3, B equals 3, and C equals 9. The confusion primarily stemmed from understanding the role of Bx in the factorization. The final values for A, B, and C are confirmed as 3, 3, and 9, respectively.
cchacon92
Messages
3
Reaction score
0
Hello, for homework I was given $$x^{3}-27$$ to factor and my answer can be written this way:

$$(x - A)(x^{2} + Bx + C)$$

I am being asked to find the value of A, B and C.
I am sure this is simpler than I think but it's perhaps the Bx that is confusing me as I haven't practiced a lot of these examples yet.
 
Mathematics news on Phys.org
Hint: Write the polynomial as the difference of cubes $x^3-3^3$ then use the difference of cubes formula $a^3-b^3=(a-b)(a^2+ab+b^2)$.
 
MarkFL said:
Hint: Write the polynomial as the difference of cubes $x^3-3^3$ then use the difference of cubes formula $a^3-b^3=(a-b)(a^2+ab+b^2)$.

Alright, so I obtained $$(x -3)(x^{2} + 3x + C)$$

I still can't find C
 
In the formula I gave for the difference of cubes, you want to substitute $x$ for $a$, and $3$ for $b$. So what does this mean $C$ is equal to?
 
9 ! Great
 
Yes, good work! (Yes)
 
Here is a little puzzle from the book 100 Geometric Games by Pierre Berloquin. The side of a small square is one meter long and the side of a larger square one and a half meters long. One vertex of the large square is at the center of the small square. The side of the large square cuts two sides of the small square into one- third parts and two-thirds parts. What is the area where the squares overlap?

Similar threads

  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 19 ·
Replies
19
Views
3K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
Replies
4
Views
1K
  • · Replies 1 ·
Replies
1
Views
1K