ML AGGARWAL CLASS 7 Chapter 8 Algebraic Expressions Exercise 8.1

 Exercise 8.1

Question 1 

(i) 3 x+6

(ii) $\quad 13-5 x$

(ii) $\quad x^{2}+y^{2}$

(iv) $\quad 3 p q+7$

(v) $\quad x^{2}-3 x$

ii) $\quad mn-(m+n)$

Question 2

A taxi charges = 9\km

fixed charges = 80

Taxo fixed for x km is 

9x + 50

Question 3

(i) $\quad 5 a-3 b+c$

(ii. $\quad x^{2}-5 x+6 .$

(iii) $x^{2} y+x y-x y^{2}$

Question 4

(i) $3,-7 x$

ii. $2,-5 a, \frac{3}{2} b$

iii, $3 x^{5}, 4 y^{3},-7 x y^{2}, 3$

Question 5

i) -4x + 5y

Term - 4x , 5y

Factor -4x  5y

ii) $\quad x y+2 x^{2} y^{2}$

Term $: x y \quad, \quad 2 x^{2} y^{2}$

'

factor: $x, y \quad 2, x, x, y, y$

iii) $1.2 a b-2.4 b+3.6 a$

Term $: 1.2 a b \quad-2.4 b \quad 3.6 a$

farror : $1.2, a, b \quad-2.4, b \quad 3.6, a$

Question 6

i) $8 x+3 y^{2}$

(to be added)

ii)$y-y^{3}$

(to be added)

iii) $5 x y^{2}+7 x^{2} y$

(to be added)

iv) $-a b+2 b^{2}-3 a^{2}$

(to be added)

Question 7

i) $-7$

ii) $-2$

iii) 6

iv) $2 / 3$

Question 8

i) $-4 b$

ii) $5 y_{2}$

iii) $-1$

iv) $-3 x y$

Question 9

i) $-y^{2} z^{3}$

ii) $72^{3}$

(iii) $-7 y z^{2}$

iv) $-x y z$

Question 10

i) Non - constant term = -7x

Numerical coefficients = -7

ii) $1+2 x-3 x^{2}$

Non-constant term $2 x,-3 x^{2}$

Numerical coefficients $=2,-3$

iii) 1.2a + 0.8 b 

Non- constant term = 1.2a , 0.8b

Numerical coefficient = 1.2, 0.8

Question 11

(i) $13 y^{2}-8 x y$

$-8 x y$

coefficient of $x=-8 y$

ii) 7x - $x y^{2}$

$7 x,-x y^{2}$

Coefficient of x = 7 $-y^{2}$

(iii)

 $\begin{aligned} 5 &-7 x y z+4 x^{2} y \\ &-7 x y z, 4 x^{2} y \end{aligned}$

Coefficient of x = -7xyz , 4xy

Question 12

i)

 $\begin{aligned} 8-x y^{2} \\-& x y^{2} \end{aligned}$

Coefficient  of $y^{2}=-x$

ii)

 $\begin{aligned} 5 y^{2} &+7 x-3 x y^{2} \\ & 5 y^{2},-3 x y^{2} \end{aligned}$

Coefficient  of $y^{2}=5,-3 x$

iii) 

$\begin{aligned} 2 x^{2} y &-15 x y^{2}+7 y^{2} \\-& 15 x y^{2}, 7 y^{2} \end{aligned}$

Coefficient  of $y^{2}=-15 x^{2}, 7$

Question 13

i) 4y-72 binomial

ii) $-5 x y^{2}$ monomial

iii) $x+y-x y \quad$ trinomial

iv) $a b^{2}-5 b-3 a$ trinomial

v) $4 p^{2} q-5 p q^{2} \quad$ binomial

(vi) 2017 monomial

(vii) $1+x+x^{2}$ trinamial

(viii) $5 x^{2}-7+3 x+4$ trinomial

Question 14

i) $-7 x, 5 / 2^{x}$ Like term 

ii) $-29 x,-29 y$ unlike term 

iii) $2 \mathrm{xy}, 2 \mathrm{xy} 2$ unlike term 

iv) $4 m^{2} p, 4 m p^{2}$ unlike term

v) $\quad 12 x z, 12 x^{2} z^{2}$ unlike term

vi) $-59 q, 79 p$ like term

Question 15

i) $x^{2} y,-2 x^{2} y$

ii) $3 a^{2} b,-6 x^{2} b, 2 a b c$, 4abc

iii) $10 p q,-7 p q, 78 q p .$

$7P,2405 P .$

$8 q,-100 q$

$-p^{2} q^{2}, 12 q^{2} p^{2}$

$-23,41$

$-5 p^{2}, 701 p^{2}$

$13 p^{2} q, q p^{2}$

Question 16

ii, 8

ii, 1

iii, 0

iv, 2

Question 17

$\begin{array}{ll}\text { (i) } & 3 \\ \text {(ii)} & 4 \\ \text ({iii)} 5\end{array}$

Question 18

i) True 

ii) False 

iii) False 

iv) False 

v) True 

vi) False 

vii) False