e-analytics.com/urchin.js" type="text/javascript">
Support the Monkey! Tell All your Friends and Teachers

Help / FAQ



Example Divide x5 + 243 by x + 3

Solution: Write the dividend in the coefficient form, and write -3 to the left of the 1st coefficient

\ x5 + 243 = ( x + 3 ) ( x4 - 3x3 + 9x2 - 27x + 81 ) + 0

FACTORING :

Factor : When a number or an expression is the product of two or more numbers or expressions, each of the latter is called a factor of the former. Thus 4 and 7 are factors of 28 and ( x + y ) and ( x - y ) are factors of x2 - y2.

Factoring or factorization is the process of changing any algebraic or numerical expression from a sum of terms into a product of factors. A number or expression is said to be prime if no factors can be obtained of that.

1. Expressions in which each term has a common factor.

We have seen that x ( a + b + c ) = x a + x b + x c.

We write this as x a + x b + x c = x ( a + b + c ) . ® ( 1 )

(1) shows that x and ( a + b + c ) are factors x a + x b + x c .

Here we notice that every term on L. H. S. of (1) contains x as a factor. The other factor ( a + b + c ) can be obtained by dividing the given expression x a + x b + x c by the common factor x .

Example Factorise 5x3 + 7x

Solution: 5x3 + 7x = x (5x2 + 7 )

Example Find the factor of ap - aq + a r

Solution: ap - aq + a r = a ( p - q + r )

Example Factorise 2m3 + 8m2 + 10m

Solution: 2m3 + 8m2 + 10m = 2m ( m2 + 4m + 10 )

Example Find the factors of 2a3b - 8a2b2

Solution: 2a3b - 8a2 b2 = 2a2 b ( a - 2b )

Example Factorise c ( a + b ) + d ( a + b ) + e ( a + b )

Solution: c ( a + b ) + d ( a + b ) + e ( a + b ) = ( a + b ) ( c                + d + e )



2. Factors by arranging terms in suitable groups.

Example Factorise ac + bc + bd + ad + ae + be

Solution: Here we cannot find a common factor. We can form suitable groups, thus expression

= ( ac + bc ) + ( ad + bd ) + ( ae + be )

= c ( a + b ) + d ( a + b ) + e ( a + b )

= ( a + b ) ( c + d + e )

or expression

= ( ac + ad + ae ) + ( bc + bd + be )

= a ( c + d + e ) + b ( c + d + e )

= ( c + d + e ) ( a + b )

= ( a + b ) ( c + d + e )

Example Resolve into factors x3 + 2x2y - 2xy2 - 4y3

Solution: x3 + 2x2y - 2xy2 - 4y3 =

= x2( x + 2y ) - 2y2 ( x + 2y )

= ( x + 2y ) ( x2 - 2y2 )

Example ax - ay - bx + by + cx - cy

Solution: expression =

= a ( x - y ) - b ( x - y ) + c ( x - y )

= ( x - y ) ( a + b + c )

Perfect squares i) ( a + b )2 = a2 + 2 ab + b2 ii) ( a - b )2 = a2 - 2 ab + b2


3. Factors of expression of the form.

a2 + 2 ab + b2 = ( a + b )2 ..... (1)

a2 - 2 ab + b2 = ( a - b )2 ......(2)

Example Factorize x2 + 4x + 4

Solution: x2 + 4x + 4=

[next page]

Index

3.1 - Introduction
3.2 - Monomial, Polynomials
3.3 - H.C.F and L.C.M

Chapter 4





All Contents Copyright © All rights reserved.
Further Distribution Is Strictly Prohibited.


Search:
Keywords:
In Association with Amazon.com