Page 147 - ICSE Math 7

MENTAL MATHS

1. Choose the correct answer.

2
(a) The expression 2 – x + x is a __________.
(i) monomial (ii) binomial (iii) trinomial (iv) none of these
2
(b) The numerical coefficient in –7xy is __________.
(i) 7 (ii) –7 (iii) –7x (iv) 7y 2
4
2
(c) The degree of the polynomial x – 3x + xy + 4 is __________.
(i) 0 (ii) 1 (iii) 2 (iv) 4
3
3
3
3
(d) The sum of x – y and y – x is __________.
3
3
3
6
3
(i) 0 (ii) 2x – 2y (iii) 2y – 2x (iv) x – y 6
3
3
(e) The value of the expression x + y when x = 1, y = –1 is __________.
(i) –1 (ii) 0 (iii) –2 (iv) 2
2. Write True or False.
(a) A quantity whose numerical value is fixed is known as a variable.
(b) The product of two constants is a constant.
2
2
(c) 6xy and –6y x are like terms.
(d) An algebraic expression which consists of three terms is known as a binomial.
(e) The degree of a polynomial is the highest constant present in the polynomial.
(f) A symbol having fixed numerical value is a constant term.
(g) Two unlike terms cannot be added to get a single term.

(h) The sum of two like terms is a term with numerical coefficient equal to the sum of the
coefficients of the like terms.
3. Fill in the blanks.
2
(a) 3ab × –1 = __________ (b) 0 × 4a p = __________
2 2
2
3 3
(c) –15p q ÷ pq = __________ (d) 52x y ÷ 4xy = __________
2
2
2
(e) lmn × lmn = __________ (f) (12a – b ) ÷ ab = __________
(g) The algebraic expression representing 2 diminished from 3 times x is ________.
(h) While subtracting two like terms, their numerical coefficients are __________________.
PRACTICE TIME

1. Classify the following expressions as monomial, binomial or trinomial.
2
2
2
3
2
(a) 2x + 5 (b) 3x (c) 2x – 4y (d) 2x + 4x + 1
2. Find the coefficient of ‘y’ in:
2
2
2
(a) 4x y (b) 3xy + 4 (c) –5x yz + xz (d) 7 – 3xy
3
2
2
3. What should be added to 4x – 3x + 5 to get x – 3x + 9?
2
2
2
2
2
3
2
4. What should be subtracted from the sum of x y + y x + 3 and –3x y + y + xy to get x y + xy – 2?
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