Page 166 - Maths Class 06

SOLUTION : (a) Thrice of a = 3 × a =3a
\ Five more than thrice of a = 3a + 5.
(b) Four times a = 4 × a = 4a
Five less than b = b – 5
\ 4a = b – 5.
ab
(c) The product of a and b divided by 9 = .
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EXAMPLE 9. The algebraic expressions m + n and m + m indicate sums. How do they differ?
SOLUTION : The expression m + m uses the same letter and shows that the first addend is the same
number as the second addend, whereas the expression m + n uses two different letters
indicating that numbers are not necessarily the same.

Exercise11.2

1. Which out the following are expressions with numbers only?
(a) x + 4 (b) 84 – 3y
(c) 8 × 14 (d) (8 12- )5 7 2+ ´

(e) 5 (f) (8 × 19) – 7y
(g) (7 × 14) + (5 × 20) + 45 + q
2. Write the following in the form of algebraic expressions:
(a) Ten less than x.
(b) Eleven added to twice y.

(c) The difference of x and y when x > y.
(d) One-fourth of x added to the sum of y and z.

(e) The product of x and y added to the sum of x and y.
3. State in words the mean ing of the following algebraic expressions:
(a) x + 7 (b) 2x – y

(c) 3ab (d) x ¸ y
4. Translate into algebraic expression:
(a) Five times x, increased by three

(b) n times six, decreased by five.
5. Ashok is k years old now. How old will he be after 5 years from now?
6. Amit is k years old. How old was he m year ago?
7. Write two algebraic expressions for ‘‘three times x’’ using two different operations.

8. A two-digit number has m in the tens place and n in the ones place. What is the number?

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