Page 165 - Maths Class 06
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Polynomials
            An expression containing two or more terms is known as polynomial.

                                                              Terms

            (a) Like Terms and Unlike Terms
            Like terms : The terms having the same literal factors are called          NOTE
            like terms or similar      terms. Such as in the expression
                              2
               2
                        2
                                      2
                                                                          2
                                                                2
                                                      2
            4x y - 3yx +   7y x -  8x y, we have 4x y, -   3yx  and -8x y as           Instead of writing 1 x, write x only.
            like or similar terms.                                                     The product of x  and y  can be
                                                                                       written as yx or xy.
            Unlike terms : The terms not having same literal factors are called
                                                                                                2
                                                                     2
                                                                             3
                                                                                                            3
            unlike or dissimilar terms. Such as in the expression 5x y -  3x y - 7, we have 5x y and -3x y as unlike
            or dissimilar terms.
            (b) Powers of Literal
                2
            In a , a is the base and 2 is the exponent.
            EXAMPLE 7.    Find out the base and exponent of the following:
                          (i)  b 2                                       (ii) c 3
                                    2
            SOLUTION :    (i)   In b , b is the base and 2 is the exponent.
                                   3
                          (ii) In c , c is the base and 3 is the exponent.
                                Application of Algebraic Expressions in Practical Problems


            We come across many practical situations in which algebraic expressions are useful. Some such practical
            situations are given below:

                               Situation                           Variable              Statement using expression


             1. Arun has 7 more balls than Nikhil.      Let Nikhil has m balls.         Arun has (m + 7) balls.

             2. Shivam    gets  20 marks less than Let Shikha get x marks.              Shivam gets (x – 20) marks.
                 Shikha.

             3. Nitin is 4 years older than Akhil.      Let Akhil’s age be n years.     Nitin’s age is (n + 4) years.


             4. Anil is thrice as old as Sudha.         Let Sudha’s age be n years.     Anil’s age is 3n years.

             5. The age of Shilpa’s  mother is 3  years Let Neha’s age be n years.      The age of Shilpa’s  mother is
                 more than twice of Neha’s age.                                         (2n+ 3) years.

            EXAMPLE 8.    Write each of the following in the form of algebraic expression:

                          (a) Five more than thrice of a
                          (b) Four times a is five less than b.
                          (c) The product of a and b divided by 9.




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