class 8 maths chapter 9 exercise 9.1
Find Solutions to class 8 maths chapter 9 exercise 9.1
class 8 maths chapter 9 exercise 9.1 (1)
Identify the terms, their coefficients for each of the following expressions.
(i) 5xyz²– 3zy (ii) 1 + x + x ² (iii) 4x²y²+4x²y²z²+z² (iv) 3 – pq + qr – rp
(v) (ˣ/₂)+(ʸ/₂)-xy (vi) 0.3a – 0.6ab + 0.5b
Solution to class 8 maths chapter 9 exercise 9.1 (1)
(i) Given expression 5xyz²– 3zy
Terms 5xyz² and –3zy
Coefficient in 5xyz² is 5 and in –3zy is -3
(ii) Terms 1,x and x².
Coefficient of x is 1 and Coefficient of x² is 1
(iii) Terms 4x²y², -4x²y²z² and z²
Coefficient in 4x²y² is 4, Coefficient in -4x²y²z² is -4, and Coefficient of z² is 1
(iv) Terms 3, -pq, qr and -rp
Coefficient of -pq is -1, Coefficient of qr is 1, and Coefficient of -rp is -1
(v) Terms ; (ˣ/₂), (ʸ/₂) and -xy
Coefficient of (ˣ/₂) is ½, Coefficient of (ʸ/₂) is ½, and Coefficient of -xy is -1
(vi) Terms 0.3a, -0.6ab and 0.5b
Coefficient of 0.3a is 0.3, Coefficient of -0.6ab is -0.6, and Coefficient of 0.5b is 0.5
class 8 maths chapter 9 exercise 9.1 (2)
Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?
x + y, 1000, x+x²+x³+x⁴, 7+y+5x, 2y-3y², 2y-3y²+4y³, 5x-4y+3xy, 4z-15z², ab + bc + cd + da, pqr, p²q+pq², 2p+2q
Solution to class 8 maths chapter 9 exercise 9.1 (2)
(i) Since x+y contains two terms. Therefore it is binomial.
(ii) Since 1000 contains one term. Therefore it is monomial.
(iii) Since x+x²+x³+x⁴, contains Four terms. Therefore it is polynomial and it does not fit in above three categories.
(iv) Since 7+y+5x contains three terms. Therefore it is trinomial.
(v) Since 2y-3y² contains two terms. Therefore it is binomial.
(vi) Since 2y-3y²+4y³ contains three terms. Therefore it is trinomial.
(vii) Since 5x-4y+3xy contains three terms. Therefore it is trinomial.
(viii) Since 4x-15z² contains two terms. Therefore it is binomial.
(ix) Since ab+bc+cd+da, contains Four terms. Therefore it is polynomial and it does not fit in above three categories.
(x) Since pqr contains one term. Therefore it is monomial.
(xi) Since p²q+pq² contains two terms. Therefore it is binomial.
(xii) Since 2p+2q contains two terms. Therefore it is binomial.
class 8 maths chapter 9 exercise 9.1 (3)
3. Add the following.
(i) ab-bc, bc-ca, ca-ab (ii)a-b+ab, b-c+bc, c-a+ac
(iii) 2p²q²-3pq+4, 5+7pq-3p²q² (iv) l²+m², m²+n², n²+l², 2lm+2mn+2nl
Solution to class 8 maths chapter 9 exercise 9.1 (3).
(i) ab-bc, bc-ca, ca-ab
ab – bc
+bc – ca
-ab +ca
0 + 0 + 0
(ii) a-b+ab, b-c+bc, c-a+ac
a – b + ab
+b -c + bc
-a +c +ac
0 +0 +ab +0 +bc+ac
(iii) 2p²q²-3pq+4, 5+7pq-3p²q²
2p²q² – 3pq + 4,
-3p²q² + 7pq + 5
-p²q² + 4pq + 9
(iv) l²+m², m²+n², n²+l², 2lm+2mn+2nl
l² + m²
+ m² + n²
+l² + n²
+ 2lm + 2mn + 2nl
2l² + 2m² + 2n² + 2lm + 2mn + 2nl
class 8 maths chapter 9 exercise 9.1 (4)
4. (a) Subtract 4a – 7ab + 3b + 12 from 12a – 9ab + 5b – 3
(b) Subtract 3xy + 5yz – 7zx from 5xy – 2yz – 2zx + 10xyz
(c) Subtract 4p ²q – 3pq + 5pq²– 8p + 7q – 10 from 18 – 3p – 11q + 5pq – 2pq²+ 5p²q
Solution to class 8 maths chapter 9 exercise 9.1 (4).
(a)
12a – 9ab + 5b – 3
4a – 7ab + 3b + 12
(-) (+) (-) (-)
8a – 2ab + 2b – 15
(b)
5xy – 2yz – 2zx + 10xyz
3xy + 5yz – 7zx
(-) (-) (+)
2xy – 7yz + 5zx + 10xyz
(c)
5p²q – 2pq² + 5pq – 11q – 3p + 18
4p²q + 5pq² – 3pq + 7q – 8p – 10
(-) (-) (+) (-) (+) (+)
p²q – 7pq² + 8pq – 18q +5p +28