Question

Difficulty: MediumFactoring Polynomials

Pair the given polynomial expressions on the left with their fully factored equivalents on the right.

  • 4x2−254x^2 - 25(2x−5)(2x+5)(2x - 5)(2x + 5)
  • x2−8x+15x^2 - 8x + 15(x−3)(x−5)(x - 3)(x - 5)
  • 3x2+12x−153x^2 + 12x - 153(x+5)(x−1)3(x + 5)(x - 1)
  • 2x3−8x2x^3 - 8x2x(x−2)(x+2)2x(x - 2)(x + 2)

Answer

The correct pairings are: 4x2−254x^2 - 25 with (2x−5)(2x+5)(2x - 5)(2x + 5); x2−8x+15x^2 - 8x + 15 with (x−3)(x−5)(x - 3)(x - 5); 3x2+12x−153x^2 + 12x - 15 with 3(x+5)(x−1)3(x + 5)(x - 1); and 2x3−8x2x^3 - 8x with 2x(x−2)(x+2)2x(x - 2)(x + 2).
Each polynomial expression was broken down into its fundamental algebraic components by identifying patterns such as the difference of squares, standard trinomial factoring, and extracting the greatest common factor.

Step-by-Step Solution

1
Analyze the first expression 4x2−254x^2 - 25.
It factors to (2x−5)(2x+5)(2x - 5)(2x + 5).
It follows the difference of squares pattern a2−b2=(a−b)(a+b)a^2 - b^2 = (a - b)(a + b) with a=2xa = 2x and b=5b = 5.
2
Analyze the second expression x2−8x+15x^2 - 8x + 15.
It factors to (x−3)(x−5)(x - 3)(x - 5).
The constant term is positive and the middle coefficient is negative, so both factors must contain negative constants that multiply to 1515 and add to −8-8.
3
Analyze the third expression 3x2+12x−153x^2 + 12x - 15.
It factors to 3(x+5)(x−1)3(x + 5)(x - 1).
Factoring out the GCF of 33 gives 3(x2+4x−5)3(x^2 + 4x - 5). The resulting quadratic factors into binomials with constants 55 and −1-1.
4
Analyze the fourth expression 2x3−8x2x^3 - 8x.
It factors to 2x(x−2)(x+2)2x(x - 2)(x + 2).
Factoring out the GCF of 2x2x gives 2x(x2−4)2x(x^2 - 4). The expression x2−4x^2 - 4 is a difference of squares that further factors into (x−2)(x+2)(x - 2)(x + 2).

Key Concept

Factoring Polynomials
Estimated Time:2m 0s
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