Factorization in Mathematics Explained in Detailed

In This Chapter We cover the all the topics and basics of factorization these are the topics we cover as follows:

    Highest Common Factor (H.C.F) of Monomials

    The H.C.F of given monomials is the common factor having greatest coefficient and highest powers of the variables.

    Ex: 1) Find H.C.F of 6x^{3}y and 18x^{2}y^{3}.

    Sol: 6x^{3}y = 2 \times 3 \times x^{3} \times y

    \quad \quad \ 18x^{2}y^{3} = 2 \times 3^{2} \times x^{2} \times y^{3}

    \quad \quad \ \text{H.C.F} = 2 \times 3 \times x^{2} \times y

    \quad \quad \quad \quad \quad \quad \ = 6x^{2}y

    Ex: 2) Find H.C.F of 5xy and 10x.

    Sol: 5xy = 5 \times x \times y

    \quad \quad \ 10x = 2 \times 5 \times x

    \quad \quad \ \text{H.C.F} = 5x

    Ex: 3) H.C.F of 12a^{2}b and 15ab^{2} is 3ab

    Ex: 4) H.C.F of 2x and 4 is 2

    Ex: 5) H.C.F of 12x and 36 is 12

    Ex: 6) H.C.F of 14pq and 35pqr is 7pq

    What is Factorization and its identities?

    Factorization is the mathematical process of expressing an algebraic expression as a product of two or more factors. Below are the 15 essential identities and methods used to break down expressions:

    Basic Methods & Linear Identities

    1. ab + ac = a(b + c)
    2. ab - ac = a(b - c)
    3. ac + ad + bc + bd = (a + b)(c + d)

    Square-Based Identities

    4. a^2 - b^2 = (a + b)(a - b)

    5. a^2 + 2ab + b^2 = (a + b)^2

    6. a^2 - 2ab + b^2 = (a - b)^2

    7. x^2 + (a + b)x + ab = (x + a)(x + b)

    8. a^2 + b^2 + c^2 + 2ab + 2bc + 2ca = (a + b + c)^2

    9. a^2 + b^2 + c^2 + 2ab - 2bc - 2ca = (a + b - c)^2

    Cubic & Advanced Identities

    10. a^3 + 3a^2b + 3ab^2 + b^3 = (a + b)^3

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

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

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

    14. a^3 + b^3 + c^3 - 3abc = (a + b + c)(a^2 + b^2 + c^2 - ab - bc - ca)

    15. If a + b + c = 0, then a^3 + b^3 + c^3 = 3abc

    Basic Methods & Linear Identities in Factorization

    1. Common Factor (Sum): The most basic form where a common term is factored out.

    ab + ac = a(b + c)

    Ex: 1) Factorize 2x + 4

    Sol:

    2x+4 = 2x+2(2)

    \quad \quad \quad \quad \quad \ = 2(x+2)

    Ex: 2) Factorize 5xy+10x

    Sol:

    5xy+10x = 5xy+5(2)(x)

    \quad \quad \quad \quad \quad \quad \quad \ = 5x(y+2)

    Ex: 3) Factorize 12a^{2}b+15ab^{2}

    Sol:

    12a^{2}b+15ab^{2} = 3\times4\times a^{2}\times b+3\times5\times a\times b^{2}

    \quad \quad \quad \quad \quad \quad \quad \quad \ \ = 3ab(4a+5b)

    2. Common Factor (Difference): Factorization involving a subtraction within the expression.

    ab - ac = a(b - c)

    Ex: 1) Factorize 22y-33z

    Sol:

    22y-33z = 11 \times 2 \times y - 11 \times 3 \times z

    \quad \quad \quad \quad \quad \ \ = 11(2y-33z)

    Ex: 2) Factorize 10x^2 - 18x^3 + 14x^4

    Sol:

    10x^2 - 18x^3 + 14x^4 = 2x^2(5 - 9x + 7x^2)

    3. Factorization by Grouping: Used for four-term expressions by grouping them into pairs.

    ac + ad + bc + bd = (a + b)(c + d)

    Ex: 1) Factorize 2xy+2y+3x+3

    Sol:

    2xy+2y+3x+3

    \quad \quad \ = 2y(x+1)+3(x+1)

    \quad \quad \ = (2y+3)(x+1)

    Ex: 2) Factorize 6xy-4y+6-9x

    Sol:

    6xy-4y+6-9x

    \quad \quad \ = 6xy-4y-9x+6

    \quad \quad \ = 2y(3x-2)-3(3x-2)

    \quad \quad \ = (2y-3)(3x-2)

    Square Based Identities in Factorization

    4. Difference of Two Squares

        \[a^2 - b^2 = (a + b)(a - b)\]

    Ex 1: 49y^2 - 36 = (7y)^2 - (6)^2 = \mathbf{(7y + 6)(7y - 6)}

    Ex 2: p^4 - 81 = (p^2 + 9)(p^2 - 9) = \mathbf{(p^2 + 9)(p - 3)(p + 3)}

    Ex 3 (Mixed): a^2 - 2ab + b^2 - c^2 = (a - b)^2 - c^2 = \mathbf{(a - b + c)(a - b - c)}

    5. Perfect Square Trinomials

    These are the results of squaring a binomial sum or difference.

    Sum Identity:

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

    Ex: x^2 + 8x + 16 = \mathbf{(x + 4)^2}

    Ex: 25m^2 + 30m + 9 = \mathbf{(5m + 3)^2}

    Difference Identity:

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

    Ex: 4y^2 - 12y + 9 = \mathbf{(2y - 3)^2}

    6. Perfect Square Trinomial (Difference): The result of squaring a binomial difference.

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

    Ex 1: Factorize 4y^2 - 12y + 9

    Sol:

    (2y)^2 - 2(2y)(3) + (3)^2 = \mathbf{(2y - 3)^2}

    Ex 2: Factorize a^2 - 2ab + b^2 - c^2

    Sol:

    (a - b)^2 - c^2 = [(a - b) + c][(a - b) - c] = \mathbf{(a - b + c)(a - b - c)}

    7. Trinomials with Constant Factors (Middle Term Splitting)

        \[x^2 + (a + b)x + ab = (x + a)(x + b)\]

    Ex 1:

    x^2 + 5x + 6 = \mathbf{(x + 3)(x + 2)}

    Ex 2:

    y^2 - 7y + 12 = \mathbf{(y - 4)(y - 3)}

    Ex 3

    (ax^2 + bx + c): 3x^2 + 10x + 3 = \mathbf{(x + 3)(3x + 1)}

    Ex 4 (Advanced):

    6x^2 + 5x - 6 = \mathbf{(2x + 3)(3x - 2)}

    Ex 5 (Substitution):

    (2a - b)^2 + 2(2a - b) - 8 = \mathbf{(2a - b - 2)(2a - b + 4)}

    8. Square of a Trinomial Standard Identity

    Factoring expressions with three variables (a, b, \text{ and } c).

    Standard Identity:

    a^2 + b^2 + c^2 + 2ab + 2bc + 2ca = (a + b + c)^2

    Ex 1:

    4a^2 + b^2 + c^2 + 4ab + 2bc + 4ac = \mathbf{(2a + b + c)^2}

    Ex 2:

    9a^2 + 4b^2 + 16 + 12ab + 16b + 24a = \mathbf{(3a + 2b + 4)^2}

    9. Square of a Trinomial Variable Signs Identity

    a^2 + b^2 + c^2 + 2ab - 2bc - 2ca = (a + b - c)^2

    • Usage: Used when the signs of the product terms involving one specific variable are negative.

    Ex: Factorize 25x^2 + y^2 + 4z^2 - 10xy - 4yz + 20zx

    Sol:

    25x^2 + y^2 + 4z^2 - 10xy - 4yz + 20zx

    \quad \quad = (5x)^2 + (-y)^2 + (2z)^2 + 2(5x)(-y) + 2(-y)(2z) + 2(2z)(5x)

    \quad \quad = \mathbf{(5x - y + 2z)^2}

    Cubic & Advanced Identities in Factorization

    10. Cube of a Binomial (Sum): Factoring a four-term perfect cubic expression.

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

    Ex: 1) Factorize 8a^3 + b^3 + 12a^2b + 6ab^2

    Sol:

    8a^3 + b^3 + 12a^2b + 6ab^2

    \quad \quad = (2a)^3 + (b)^3 + 3(2a)^2(b) + 3(2a)(b)^2

    \quad \quad = \mathbf{(2a + b)^3}

    11. Cube of a Binomial (Difference): The cubic version of the subtraction identity.

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

    Ex: 1) Factorize 27 - 125a^3 - 135a + 225a^2

    Sol:

    27 - 125a^3 - 135a + 225a^2

    \quad \quad = (3)^3 - (5a)^3 - 3(3)^2(5a) + 3(3)(5a)^2

    \quad \quad = \mathbf{(3 - 5 a)^3}

    12. Sum of Two Cubes: Breaking down the sum of two cubic terms.

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

    Ex: 1) Factorize y^3 + 125

    Sol:

    y^3 + 125 \quad \quad

    = (y)^3 + (5)^3 \quad \quad

    = (y+5)(y^2 - y(5) + (5)^2) \quad \quad

    = \mathbf{(y+5)(y^2 - 5y + 25)}

    13. Difference of Two Cubes: Breaking down the subtraction of two cubic terms.

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

    Ex: 1) Factorize \frac{x^3}{216} - 8y^3

    Sol:

    \frac{x^3}{216} - 8y^3

    = \left(\frac{x}{6}\right)^3 - (2y)^3 \quad \quad \quad \quad \quad \ \

    = \left(\frac{x}{6} - 2y\right) \left[ \left(\frac{x}{6}\right)^2 + \frac{x}{6}(2y) + (2y)^2 \right] \quad \quad \quad \quad \quad \ \

    = \mathbf{\left(\frac{x}{6} - 2y\right) \left( \frac{x^2}{36} + \frac{xy}{3} + 4y^2 \right)}

    14. The Long Cubic Identity: A complex identity involving three variables.

    a^3 + b^3 + c^3 - 3abc = (a + b + c)(a^2 + b^2 + c^2 - ab - bc - ca)

    Ex: 1) Factorize a^{3}-b^{3}+1+3ab

    Sol: a^{3}-b^{3}+1+3ab

    \quad \quad = (a)^{3}+(-b)^{3}+(1)^{3}-3(a)(-b)(1)

    \quad \quad = (a-b+1)(a^{2}+(-b)^{2}+(1)^{2}-a(-b)-(-b)(1)-(1)(a))

    \quad \quad = \mathbf{(a-b+1)(a^{2}+b^{2}+1+ab+b-a)}

    15. Conditional Cubic Property: A special rule applied when the sum of the variables is zero.

    If a + b + c = 0, then a^3 + b^3 + c^3 = 3abc

    Ex: 1) Factorize (x-y)^{3}+(y-z)^{3}+(z-x)^{3}

    Sol: (x-y)^{3}+(y-z)^{3}+(z-x)^{3}

    \quad \quad = a^{3}+b^{3}+c^{3} \text{ where } a+b+c = x-y+y-z+z-x = 0

    \quad \quad = 3abc

    \quad \quad = \mathbf{3(x-y)(y-z)(z-x)}

    Division of Algebraic Expressions

    Division of a monomial by another monomial by using factorisation

    Ex: 1) Divide 6x^3 by 2x

    Sol:

    \frac{6x^3}{2x} = 3x^2

    2) Divide -20x^4 by 10x^2

    Sol:

    \frac{-20x^4}{10x^2} = -2x^2

    3) Divide 7x^2y^2z^2 by 14xyz

    Sol:

    \frac{7x^2y^2z^2}{14xyz} = \frac{xyz}{2}

    Division of Polynomial by a monomial by using factorisation

    Ex: 1) Divide 24(x^2yz + xy^2z + xyz^2) by 8xyz

    Sol:

    \frac{24(x^2yz + xy^2z + xyz^2)}{8xyz}

    \quad \quad = \frac{24xyz(x+y+z)}{8xyz}

    \quad \quad = \mathbf{3(x+y+z)}

    Ex: 2) Divide 3y^8 - 4y^6 + 5y^4 by y^4

    Sol:

    \frac{3y^8 - 4y^6 + 5y^4}{y^4}

    \quad \quad = \frac{{y^4}(3y^4 - 4y^2 + 5)}{{y^4}}

    \quad \quad = \mathbf{3y^4 - 4y^2 + 5}

    Share:

    Leave A Reply

    Your email address will not be published. Required fields are marked *

    3 × five =

    Categories

    maths tuition point in vijayawada

    You May Also Like

    Exponents can feel a bit like that one friend who over-exaggerates everything. You start with a small number, toss a...