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So, x = 9 is the solution of the equation 2x – 13 = 5.

Since, x was representing Pihu didi's present age. Thus,
Pihu didi’s present age is 9 years. Quick Check
Find a solution of the simple
Hence, a number when substituted for the variable in an x
28 using trial
equation, makes LHS = RHS to satisfy the equation is called equation 2 +=
the solution of the equation. and error method.

This method to find the solution of a simple equation is called Trial and Error method.
Example 5: Check whether the value given in the brackets is a solution to the given equation or not.
m
(a) 3x – 7 = 8 (x = 5) (b) 7 + 4p = 15 (p = –3) (c) + 3 = 5 (m = 4)
2
Solution: (a) Putting x = 5 on LHS, we get

LHS = 3x – 7 = 3 × 5 – 7 = 15 – 7 = 8
And RHS = 8. Thus, for x = 5, LHS = RHS
Maths Talk
Hence, x = 5 is the solution of the given equation.
Play with your friend. Ask him/her to
(b) Putting p = –3 on LHS, we get • think any number.

LHS = 7 + 4p = 7 + 4 × (–3) = 7 – 12 = – 5 • multiply it by 7.
And RHS = 15. Thus, for p = –3, LHS ≠ RHS • subtract 14 from the product.
Now, ask the result obtained.
Hence, p = –3 is not the solution of the given Now, you tell the number that was
equation. thought by him/her. Change your turn
(c) Putting m = 4 on LHS, we have and make more such riddles and try
to solve them. Can you guess what
m 4 concept of mathematics do you use
LHS = + 3 = + 3 = 2 + 3 = 5
2 2 to solve this riddle?
And RHS = 5. Thus, for m = 4, LHS = RHS
Hence, m = 4 is the solution of the given equation.

Practice Time 6A

1. Express the following statements as simple equation:
(a) 8 more than the number x gives 17.

(b) 3 times of y decreased by 9 gives 13.
(c) Two times of m subtracted from the 8, we get 7.
(d) 11 subtracted from the product of p and 3 gives 32.

(e) The quotient of a number x more than 1 and 3 is three-fourth of the number x.
2. Write the following equations in statement form.
3n
(a) 7+ x = 63 (b) 3x – 1 = 16 (c) 1 + 4y = 29 (d) = 6
5
1 t 3k
(e) 2u – 1 = (f) + 1 = 4 (g) 2m – 7 = 0 (h) −= 6
7
2 3 4

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