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                           (d)  The product of 4 and y is 4y. When 6 is subtracted from 4y, the difference is 60.

                               Therefore, the equation is 4y – 6 = 60.
                                                                     1
                                                                          3
                           (e)  The sum of 3 and one-third of a is  a + .
                                                                     3                        Maths Talk
                               The sum is 30. Therefore, the equation is                  How can you differentiate
                                1               a                                         between an expression and
                                      3
                                                    3
                                 a +  = 30 or  +=       30.                               simple equation? Discuss.
                                3               3
                Example 4: Convert the following equations in statement form:
                                                                                2p                     a − 3
                           (a)  x + 3 = 11           (b)  2y – 7 = 13      (c)     =  8           (d)       = 4
                                                                                3                       2
                Solution: (a)  x + 3 = 11  ⇒ 3 added to a number x gives 11.
                           (b)  2y – 7 = 13  ⇒ 7 subtracted from the twice of y gives 13.

                                2p
                           (c)     =  8  ⇒ The quotient of double of p and 3 is 8.
                                 3                                                            Think and Answer

                                a − 3                                                      In a Maths unit test, the highest
                           (d)       = 4  ⇒ The difference of a and 3 divided by
                                 2                                                         marks obtained by a student
                               2 gives 4 as quotient.                                      in the class is 7 more than the
                                                                                           twice of the lowest marks. The
                Solution of a Simple Equation                                              highest score is 18. Make an
                                                                                           equation for the given statement.

                Mother to Aarav: Let us find out Pihu didi’s present age.

                Let us substitute the different values of the variable x which represents the Pihu’s present age one
                by one in the equation 2x – 13 = 5.

                                                                                Whether the Equation is satisfied.
                   Variable (x)       LHS = 2x – 13          RHS = 5
                                                                                      Yes / No. (LHS = RHS)

                        1             2 × 1 – 13 = –11           5                          –11 ≠ 5, No
                        2             2 × 2 – 13 = –9            5                          –9 ≠ 5, No

                        3             2 × 3 – 13 = –7            5                          –7 ≠ 5, No
                        4             2 × 4 – 13 = –5            5                          –5 ≠ 5, No

                        5             2 × 5 – 13 = –3            5                          –3 ≠ 5, No
                        6             2 × 6 – 13 = –1            5                          –1 ≠ 5, No

                        7              2 × 7 – 13 = 1            5                           1 ≠ 5, No

                        8              2 × 8 – 13 = 3            5                           3 ≠ 5, No
                        9              2 × 9 – 13 = 5            5                           5 = 5, Yes

                From the above table, we observe that the value of expression in LHS is equal to RHS (= 5)
                only when we substitute x = 9 in the given expression of LHS, that is in 2x – 13. For all other
                values LHS ≠ RHS.


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