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3
3. Assertion (A): The value of x – 2x + 1, when x = 1 is zero.
3
Reason (R): (1) – 2(1) + 1 = 0
C. Match the following.

Column A Column B
(a) The difference of 3 and a number (i) 4 – 2x
2
(b) 5 less than twice a number squared (ii) x – 3
(c) Five minus thrice a number (iii) 2a – 5
2
(d) Four minus a number multiplied by 2 (iv) 5 – 3m

(e) Seven times the sum of a number and 1 (v) 3 – p
(f) A number squared plus 6 (vi) 2(x + 6)
(g) 2 times the sum of a number and 6 (vii) 7(t + 1)
2
(h) Three less than the square of a number (viii) a + 6
D. Answer the following.
1. Find the value of the following polynomials when a = 2, b = –3 and c = –1.

3
2
(a) 2a – b + 3abc (b) a + c − b 2 (c)   a + b − c  4
3
2

2  b c a
2. The cost of 1 pen is `x and the cost of 1 pencil is `y. Find the cost of 3 dozen pen and 2 dozen pencils
together. If x = 3 and y = 2. Evaluate the cost in rupees.
3. At a concert, there were x men and twice the number of women. During the interval, 5 men and 7
women left the concert.
(a) How many people left during the interval?
(b) How many people were there at the concert after the interval?

(c) If x = 700, how many people were there at the concert after the interval?
4. Write an expression for the sum of 1 and twice a number n. If you let n be any odd number, will the
result always be an odd number?
5. The rate of planting the grass is `x per square metre. Find the cost of planting the grass on a triangular
lawn whose base is y metres and height is z metres.
x + 2
6. Leena wrote an algebraic expression for “5 less than twice of a number x divided by 3” as − 5 .
What error did she make? 3
7. Shubham works in a mall and gets paid `50 per hour. Last week he worked for 7 hours and this week
he will work for x hours. Write an algebraic expression for the money paid to him for both the week.
1 1
2
8. The sum of first n natural numbers is given by n + n . Find the
2 2
(a) The sum of first 5 natural numbers (b) The sum of natural numbers from 13 to 29
9. Find the perimeter of the figure given below:

A (5x – y) D

2(x + y) 2(x + y)

B (5x – y) C

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