Haryana State Board HBSE 8th Class Maths Solutions Chapter 9 Algebraic Expressions and Identities Ex 9.1 Textbook Exercise Questions and Answers.

## Haryana Board 8th Class Maths Solutions Chapter 9 Algebraic Expressions and Identities Exercise 9.1

Question 1.

Identify the terms, their coefficients for each of the following expressions:

(i) 5xyz^{2} – 3zy

(ii) 1 + x + x^{2}

(iu) 4x^{2}y^{2} – 4x^{2}y^{2}z^{2} + z^{2}

(iv) 3 – pq + qr – rp

(v) \(\frac{x}{2}\) + \(\frac{y}{2}\) – xy

(v) 0.3a – 0.6ab + 0.5b.

Solution:

(i) There are two terms; 5xyz^{2} and -3zy

Coefficient of 5xyz^{2} = 5

Coefficient of-3zy = -3

(ii) There are three terms; 1, x and x^{2}

Coefficient of x = 1

Coefficient of x^{2} = 1

(iii) There are three terms; 4x^{2}y^{2}, -4x^{2}y^{2}z^{2}, z^{2}.

Coefficient of 4x^{2}y^{2} = 4

Coefficient of -4x^{2}y^{2}z^{2} = -4

Coefficient of z^{2} = 1

(iv) There are four terms; 3, -pq, qr and – rp.

Coefficient of -pq = -1

Coefficient of qr = 1

Coefficient of -rp = -1.

(v) There are three terms; \(\frac{x}{2}\) , \(\frac{y}{2}\), -xy

Coefficient of \(\frac{x}{2}\) = \(\frac{1}{2}\)

Coefficient of \(\frac{y}{2}\) = \(\frac{1}{2}\)

Coefficient of-xy = -1

(vi) There are three terms; 0.3a, -0.6ab, 0.5b.

Coefficient of 0.3a = 0.3

Coefficient of-0.6a6 = -0.6 .

Coefficient of 0.56 = 0.5.

Question 2.

Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories ?.

x + y, 1000, x + x^{2} + x^{3} + x^{4}, 7 + y + 5x, 2y – 3y^{2}, 2y – 3y^{2} + 4y^{3}, 5x – 4y + 3xy, 4z – 15z^{2}, ab + bc + cd + da, pqr, p^{2}q + pq^{2}, 2p + 2q.

Solution:

Monomial = 1000, par

Binomial = x + y, 2y – 3y^{2}, 4z – 15z^{2}, p^{2}q + pq^{2}, 2p + 2q

Trinomial = 7 + y + 5x, 2y – 3y^{2} + 4y^{3}, 5x – 4y + 3xy

Polynomial = x + x^{2} + x^{3} + x^{4}, ab + bc + cd + da,

Question 3.

Add the following :

(i) ab – bc, bc – ca, ca – ab

(ii) a – b + ab, b – c + bc, c – a + ac

(iii) 2p^{2}q^{2} – 3pq + 4, 5 + 7pq – 3p^{2}q^{2}

(iv) l^{2} + m^{2}, m^{2} + n^{2}, n^{2} + l^{2}, 2lm + 2mn + 2nl.

Solution:

(i) Add :

Question 4.

(a) Subtract 4a – 7ab + 36 + 12 from 12a – 9ab + 5b – 3

(6) Subtract 3xy + 5yz – 7zx from 5xy – 2yz – 2zx + 10xyz

(c) Subtract 4p^{2}q – 3pq + 5pq^{2} – 8p + 7q – 10 from 18 – 3p – 11q + 5pq – 2pq^{2} + bp^{2}q.

Solution:

(a)