Polynomials Class 9 MCQ with Answers

Polynomials Class 9 MCQ with Answers – Maths Class 9 MCQ Online Test are covered in this Article. Polynomials Class 9 MCQ Test contains 30 questions. Answers to MCQ on Polynomials Class 9 are available after clicking on the answer. MCQ Questions for Class 9 with Answers have been made for Class 9 students to help check the concept you have learnt from detailed classroom sessions and application of your knowledge.

Board CBSE
Textbook Maths (NCERT)
Class Class 9
Chapter Chapter 2 Polynomials
Category MCQ Questions for Class 9 Maths with Answers

Polynomials Class 9 MCQ with Answers

1. The constant polynomial 0 is a

(a) Linear polynomial

(b) Zero polynomial

(c) Quadratic polynomial

(d) Monomial polynomial

Answer

Answer: (b) Zero polynomial


 

2. The degree of the polynomial (x2 – 1) (x3– x4– x +1) is

(a) 3

(b) 4

(c) 5

(d) 6

Answer

Answer: (d) 6

Explanation: The highest degree variable in first bracket is x2 and in second bracket is x4 on multiplying x2 with x4.the highest power we obtain is 6.


 

3. A zero of a polynomial need to be 0.

(a) True

(b) False

Answer

Answer: (b) False

Explanation: A zero of a polynomial need not to be 0.


 

4. The zeroes of the quadratic polynomial x2 + 4x +4 are
(a)  both positive
(b) both negative
(c)  one positive and one negative
(d)  both equal

Answer

Answer: (b) both negative

Explanation:

p(x)=x2 + 4x +4

x2 + 4x +4 =0

x2 + 2x +2x+4=0

x(x+2) +2(x+2) =0

(x+2) (x+2) =0

X= -2; -2





5. The zeroes of polynomial depend on its

(a) No. of terms

(b) Degree

(c) Both

(d) None

Answer

Answer: (b) Degree

Explanation:

polynomial Degree zeroes

 

Linear 1 1
Quadratic 2 2
Cubic 3 3
……so on

 

6. Find the zero of the polynomial 3x + 4.

(a) -4/3

(b) 3

(c) 4

(d) -3/4

Answer

Answer: (a) -4/3

Explanation:

p(x) = 0

3x +4 =0

x = -4/3


 

7. The polynomial of degree 3 has at most how many zeroes

(a) 3

(b) 2

(c) 1

(D) 0

Answer

Answer: (a) 3


 

8. The zeroes of the quadratic polynomial 6x² + 11x – 35 are

(a) both positive

(b)  both negative

(c)  one positive and one negative

(d)  both equal

Answer

Answer: (c)  one positive and one negative

Explanation:

p(x)= 6x² + 11x – 35

6x² + 11x – 35 =0

6x² + 21x – 10x – 35 =0

3x(2x+7) -5(2x+7) =0

(2x+7) (3x-5) =0

X= -7/2; 5/3


 

9. If the zeroes of the quadratic polynomial x2– ax + b are 5 and –7, then

(a)  a = –2, b = –10

(b)  a = 5, b = –10

(c)  a = -2, b = –35

(d)  a = 7, b = – 6

Answer

Answer: (c)  a = -2, b = –35

Explanation:

p(x)= x2 – ax + b

When, p (5) = 52 – 5a + b = 25 -5a + b

=> 5a – b = 25…………(i)

P (-7) = (-7)2 + 7a + b = 49 + 7a +b

=> 7a + b = -49 ………..(ii)

From adding (i) & (ii), we get

12a = – 24

=> a = -2

Putting the value of a in (ii),

7 × (-2) + b = -49

=> b = -49 + 14 = -35


 

10. Find p (-1), for (x3– 1).

(a) 2

(b)  -1

(c)  -2

(d)  0

Answer

Answer: (c)  -2

Explanation:

p(x) = x3– 1

P (-1) = (-1)3 -1 = -1 -1 = -2


 

Polynomials Class 9 MCQ with Answers

11. Check whether x = -1/√3 is a zero of which polynomial

(a) -2x +3

(b) -3x + 1

(c) X2 + 3

(d) 3x2 – 1

Answer

Answer: (d) 3x2 – 1

Explanation:

p(x) = 3x2 – 1

P ((-1)/(√3)) = 3 × ((-1)/(√3))2 – 1 = 3 × 1/3 – 1 = 1-1 = 0


 

13. If (x+1) is a factor of polynomial 3x 2 -9x +k, Find the value of k.

(a)  -12

(b)  6

(c)  3

(d)  -6

Answer

Answer: (a)  -12

Explanation:

p(x) = 3x2 -9x +k

If (x+1) is a factor of polynomial 3x2 -9x +k

Then, x+1 = 0

x = -1 is a zero of the polynomial.

p (-1) = 3(-1)2 -9×(-1) +k = 3 + 9 +k = 12+k

12+ k = 0

K = -12


 

14. bx 2 + cx + a is a polynomial with …………variables.

(a) four

(b)  three

(c)  two

(d)  one

Answer

Answer: (d)  one

Explanation: The polynomial bx2 + cx1 + ax0, has only x variable with powers as whole numbers 2,1,0.


 

15. The value of p(t)= t2-7t+2, when t = -2 is

(a) -25

(b) 20

(c) 51

(d) 34

Answer

Answer: (b) 20

Explanation:

p(t)= t2-7t+2

P (-2) = (-2)2 – 7(-2) +2 = 4 +14 +2 = 20





16. Factorize x2-8x+15, by splitting method.

(a) (x -3) (x-5)

(b) (x +3) (x+5)

(c) (x-15) (x-1)

(d) (x+1) (3x+5)

Answer

Answer: (a) (x -3) (x-5)

Explanation: x2-8x+15

Here, a +b = -8, ab = 15

So, the possible factor is (3,5)

x2-8x+15 = x2 – 3x – 5x +15 = x(x-3) -5(x-3) = (x-3) (x-5)


 

17. x2 – y2 =…………..

(a) x2 -2xy + y2

(b) (y + x) (y-x)

(c) (x+ y) (x-y)

(d) 1

Answer

Answer: (c) (x+ y) (x-y)


 

18. The number of polynomials having two zeroes 2 and -1 is

(a) 1

(b) 2

(c) 3

(d) infinite

Answer

Answer: (d) infinite

Explanation: The formed quadratic polynomial having two zeroes is infinite.


 

19. (x + a) (x-b) = ………………

(a) x2 + (a – b) x + ab

(b) x2 + (a – b) x – ab

(c) x2 + (a + b) x + ab

(d) x2 + (a + b) x – ab

Answer

Answer: (b) x2 + (a – b) x – ab

Explanation: (x+ a) (x-b) = x2 + ax – bx – ab = x2 + (a – b) x – ab


 

20. Expand (4a – 5b +6c )2

(a) 16a2 + 25b2 + 36c2 – 40ab + 60bc + 48ca

(b) 8a2 + 25b2 + 16c2 – 40ab – 60bc + 48ca

(c) 16a2 + 25b2 + 36c2 – 40ab – 60bc + 48ca

(d) None of the above

Answer

Answer: (c) 16a2 + 25b2 + 36c2 – 40ab – 60bc + 48ca

Explanation:

Using, (x +y +z)2 = x2 + y2 + z2 + 2xy + 2yz + 2zx

(4a – 5b +6c )2 = (4a)2 + (-5b)2 + (6c)2 + 2 x4a x(-5b) + 2 x(-5b) x6c + 2 x6c x4a

= 16a2 + 25b2 + 36c2 – 40ab – 60bc + 48ca


 

Polynomials Class 9 MCQ with Answers

21. 27x3 + 125y3 = (3x + 5y) ………….

(a) (9x2 + 25y2 +15xy)

(b) (3x + 5y) (9x2 + 25y2 -15xy)

(c) (3x – 5y)2

(d) (9x2 + 25y2 -15xy)

Answer

Answer: (d) (9x2 + 25y2 -15xy)

Explanation:

Using, x3 + y3 = (x+ y)3 – 3xy (x+ y)

27x3 + 125y3 = (3x)3 + (5y)3

= (3x + 5y)3 – 3×3x × 5y (3x + 5y)

= (3x + 5y)3 – 45xy (3x + 5y)

= (3x + 5y) {(3x + 5y)2 – 45xy}

[(a+ b)2 = a2+ b2 +2ab]

= (3x + 5y) [{(3x)2 + (5y)2 + 2(3x) (5y)} – 45xy]

= (3x + 5y) {9x2 + 25y2 + 30xy – 45xy}

= (3x + 5y) (9x2 + 25y2 -15xy)


 

22. If one of the zeroes of the quadratic polynomial (k+1) x² + k x + 1 is – 3, then the value of k is

(a) 4

(b) 3/5

(c) -5/3

(d) -5

Answer

Answer: (c) -5/3

Explanation:

p(x)= (k+1) x² + k x + 1

P (-3) = 0

(k+1) (-3) ² + k (-3) + 1 = 0

9k + 9 -3k +1 = 0

6k + 10 = 0

k = – 10/6 = – 5/3


 

23. If one of the zero of the quadratic polynomial ax² + bx is zero, the other zero is

(a) a

(b) -b/a

(c) c/a

(d) 0

Answer

Answer: (b) -b/a

Explanation:

p(x) = ax² + bx
P (0) = 0
ax² + bx = 0
ax² = – bx
x = – b/a


 

24. Expand (6p – 7q)3

(a) 216p3 – 343q3

(b) 36p3 – 49q3 – 56p2q + 82pq2

(c) 216p3 – 343q3 – 756p2q + 882pq2

(d) 216p3 – 343q3 + 756p2q + 882pq2

Answer

Answer: (c) 216p3 – 343q3 – 756p2q + 882pq2

Explanation:

Using, (a-b)3 = a3 – b3 – 3ab (a – b)

(6p – 7q)3 = (6p)3 – (7q)3 – 3(6p) (7q) (6p – 7q)

= 216p3 – 343q3 – 126pq (6p – 7q) = 216p3 – 343q3 -756p2q + 882pq2





25. Evaluate 107 x 93.

(a) 9951

(b) 1091

(c) 9091

(d) 9591

Answer

Answer: (a) 9951

Explanation:

107 x 93 = (100+7) x (100-7)

Using, (a + b) (a-b) = a2 – b2

(100+7) x (100-7) = (100)2 – (7)2 = 10000 – 49 = 9951


 

26. If a and b are the zeroes of quadratic polynomial x2+x-6, then

(a) a +b =ab

(b) a – b =ab

(c) a +b >ab

(d) a + b <ab

Answer

Answer: (c) a +b >ab

Explanation:

x2+x-6

P(a)= x2+x-6 P(b)= x2+x-6
a2+a-6 = 0

a2+3a – 2a -6= 0

a (a+3) -2(a+3) = 0

(a+3) (a-2) = 0

a = -3 ,2

b2+b-6 = 0

b2+3b – 2b -6= 0

b (b+3) -2(b+3) = 0

(b+3) (b-2) = 0

b = -3 ,2

Let,

a= -3, b=2 a= 2, b = -3
a +b= -3+2 = -1

a-b = -3-2 = -5

ab = (-3) × 2= -6

a +b = 2 -3 = -1

a-b = 2+3 = 5

ab = -6

 a + b >ab = -1>-6


27. Evaluate 173 – 193

(a) -1946

(b) 1938

(c) 1946

(d) 946

Answer

Answer: (a) -1946

Explanation:

Using, a3 – b3= (a-b)3 +3ab(a-b)

173 – 193 = (17-19)3 + 3 × 17 ×19 (17 -19)

= (-2)3 + 3×17×19×(-2)

= -8 – 1938

= – 1946


 

28. Factorize: 3x2 + 5y2 + 4z2 + 2√15 x y – 4√5yz – 4√3zx

(a)  (√3x – √5y – 2z )2

(b)  (√3x + √5y + 2z )2

(c)  (√3x + √5y – 2z )2

(d)  (√3x – √5y + 2z )2

Answer

Answer: (c)  (√3x + √5y – 2z )2

Explanation:

3x2 + 5y2 + 4z2 + 2√15 x y – 4√5yz – 4√3zx

= (√3x)2 + (√5y)2 + (-2z)2 + 2(√3x) (√5y) + 2(√5y) (-2z) + 2(-2z) (√3x)

Using, (x + y + z)2 = x2 + y2 + z2 + 2xy + 2yz +2zx

= (√3x + √5y – 2z )2


 

29. Find the zero of the polynomial: px + q

(a) -p/q

(b) p/q

(c) -1

(d) -q/p

Answer

Answer: (d) -q/p

Explanation: p(x) = px +q
px +q = 0
x = -q/p


 

30. If p and q are zeroes of polynomial 3x2-4x-4, then find p +q + p q.

(a) -4/3

(b) 3/4

(c) 0

(d) 2/3

Answer

Answer: (c) 0

Explanation:

p(x)= 3x2-4x-4

3x2-4x-4 = 0

3x2– 4x – 4 =0

3X2 – 6x + 2x – 4 = 0

3x (x-2) +2 (x-2) =0

(x-2) (3x+2) =0

X = 2, -2/3

p + q +p q = 2 + ((-2)/3) + 2((-2)/3)

= 2 – 2/3 – 4/3

= 0


 

MCQ Questions for Class 9 Maths

Frequently Asked Questions on Polynomials Class 9 MCQ with Answers

1. Are these MCQ on Polynomials Class 9 are based on 2021-22 CBSE Syllabus?

Yes. There are 30 MCQ’s on this Chapter in this blog.

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