Math Problem Statement

explain factoring

Solution

Factoring is the process of breaking down an expression into simpler components, called factors, that can be multiplied together to give the original expression. It's often used to simplify expressions, solve equations, or find roots of polynomials.

Types of Factoring:

  1. Factoring out the Greatest Common Factor (GCF):

    • First, look for the largest number or variable that is common to all terms in the expression.
    • Example: Factor the expression 6x2+9x6x^2 + 9x.
      • The GCF of 6x26x^2 and 9x9x is 3x3x.
      • Factor out 3x3x:
        6x2+9x=3x(2x+3)6x^2 + 9x = 3x(2x + 3)
  2. Factoring Trinomials:

    • For expressions of the form ax2+bx+cax^2 + bx + c, we find two numbers that multiply to acac and add to bb.
    • Example: Factor x2+5x+6x^2 + 5x + 6:
      • We need two numbers that multiply to 66 (the constant term) and add up to 55 (the coefficient of the middle term).
      • These numbers are 22 and 33, because 2×3=62 \times 3 = 6 and 2+3=52 + 3 = 5.
      • So, we rewrite the middle term as:
        x2+2x+3x+6x^2 + 2x + 3x + 6
      • Now group the terms:
        (x2+2x)+(3x+6)(x^2 + 2x) + (3x + 6)
      • Factor each group:
        x(x+2)+3(x+2)x(x + 2) + 3(x + 2)
      • Factor out the common binomial (x+2)(x + 2):
        (x+2)(x+3)(x + 2)(x + 3)
  3. Difference of Squares:

    • This is a special case of factoring where you factor expressions of the form a2b2a^2 - b^2.
    • The formula for this is: a2b2=(ab)(a+b)a^2 - b^2 = (a - b)(a + b)
    • Example: Factor x29x^2 - 9:
      • x29x^2 - 9 is a difference of squares, where a=xa = x and b=3b = 3.
      • So, we factor it as:
        x29=(x3)(x+3)x^2 - 9 = (x - 3)(x + 3)
  4. Perfect Square Trinomial:

    • If a trinomial is of the form a2+2ab+b2a^2 + 2ab + b^2, it factors as: (a+b)2(a + b)^2
    • If the trinomial is of the form a22ab+b2a^2 - 2ab + b^2, it factors as: (ab)2(a - b)^2
    • Example: Factor x2+6x+9x^2 + 6x + 9:
      • This is a perfect square trinomial where a=xa = x and b=3b = 3.
      • So, we factor it as:
        x2+6x+9=(x+3)2x^2 + 6x + 9 = (x + 3)^2
  5. Sum or Difference of Cubes:

    • For expressions of the form a3+b3a^3 + b^3 or a3b3a^3 - b^3, there are special formulas:
      • a3+b3=(a+b)(a2ab+b2)a^3 + b^3 = (a + b)(a^2 - ab + b^2)
      • a3b3=(ab)(a2+ab+b2)a^3 - b^3 = (a - b)(a^2 + ab + b^2)
    • Example: Factor x38x^3 - 8:
      • Recognize that 8=238 = 2^3, so this is a difference of cubes.
      • Factor it as:
        x38=(x2)(x2+2x+4)x^3 - 8 = (x - 2)(x^2 + 2x + 4)

Why is Factoring Important?

  • Factoring helps simplify algebraic expressions and solve polynomial equations, particularly quadratic equations. It also plays a crucial role in finding the roots of a polynomial.

Do you want me to go over any specific type of factoring or example in more detail?


Here are some related questions for you to explore:

  1. How do you factor quadratic equations with leading coefficients other than 1?
  2. Can factoring help in solving rational equations?
  3. What are the key steps in factoring a polynomial with four terms?
  4. How do you factor a binomial when both terms are perfect cubes?
  5. How do you recognize and factor a perfect square trinomial?

Tip: Always start factoring by looking for a GCF (Greatest Common Factor) before attempting more complex factoring methods. It often simplifies the problem significantly!

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Math Problem Analysis

Mathematical Concepts

Algebra
Factoring
Polynomials
Trinomials
Difference of Squares
Sum and Difference of Cubes
Perfect Square Trinomial

Formulas

a^2 - b^2 = (a - b)(a + b)
(a + b)^2 = a^2 + 2ab + b^2
(a - b)^2 = a^2 - 2ab + b^2
a^3 + b^3 = (a + b)(a^2 - ab + b^2)
a^3 - b^3 = (a - b)(a^2 + ab + b^2)

Theorems

Factoring trinomials
Difference of squares
Sum and difference of cubes
Perfect square trinomials

Suitable Grade Level

Grades 7-10