# Class 8 Maths Chapter 9 Algebraic Expressions and Identities MCQs

**Class 8 Maths Chapter 9 Algebraic Expressions and Identities MCQs (Questions and Answers)** are provided online here for students. These multiple-choice questions have been designed by experts referring to the latest **CBSE **syllabus (2021-2022) and **NCERT **guidelines. The objective questions are provided chapter-wise at BYJU’S. Also, learn important questions for class 8 Maths here.

Practice more and test your skills on Class 8 Maths Chapter 9 Algebraic Expressions and Identities MCQs with the given PDF here.

## MCQs Questions on Class 8 Algebraic Expressions and Identities

Multiple choice questions (MCQs) are available for Class 8 chapter 9 Algebraic Expressions and Identities chapter. For all the problems, there are four multiple options given among which one is the right answer. Solve each question and choose the correct answer.

**1. An algebraic expression that contains only one term is called:**

A. Monomial

B. Binomial

C. Trinomial

D. None of the above

Answer:** A**

Example: 2x is a monomial

**2. 5x+6y is a:**

A. Monomial

B. Binomial

C. Trinomial

D. None of the above

Answer: **B**

Explanation: The expression containing two terms is called binomial.

**3. The algebraic expression 3x+2y+6 is a:**

A. Monomial

B. Binomial

C. Trinomial

D. None of the above

Answer:** C**

Explanation: The algebraic expression containing three terms is called a trinomial. Here, 3x, 2y and 6 are three terms.

**4. A polynomial contains _______ number of terms:**

A. One

B. Two

C. Three

D. Any

Answer:** D**

Explanation: A polynomial can contain any number of terms, i.e. one or more than one.

**5. In which of the following, the two expressions are like terms?**

A. 7x and 7y

B. 7x and 9x

C. 7x and 7x^{2}

D. 7x and 7xy

Answer: **B**

**6. If we add, 7xy + 5yz – 3zx, 4yz + 9zx – 4y and –3xz + 5x – 2xy, then the answer is:**

A. 5xy + 9yz +3zx + 5x – 4y

B. 5xy – 9yz +3zx – 5x – 4y

C. 5xy + 10yz +3zx + 15x – 4y

D. 5xy + 10yz +3zx + 5x – 6y

Answer: **A**

Explanation: Given, 7xy + 5yz – 3zx, 4yz + 9zx – 4y and –3xz + 5x – 2xy.

If we add the three expressions, then we need to combine the like terms together.

(7xy – 2xy) + (5yz + 4yz) – 3zx + 9zx – 3xz – 4y + 5x

= 5xy + 9yz + 3zx + 5x – 4y

**7. If we subtract 4a – 7ab + 3b + 12 from 12a – 9ab + 5b – 3, then the answer is:**

A. 8a+2ab+2b+15

B. 8a+2ab+2b-15

C. 8a-2ab+2b-15

D. 8a-2ab-2b-15

Answer:** C**

Explanation: (12a – 9ab + 5b – 3) – (4a – 7ab + 3b + 12)

= 12a – 9ab + 5b – 3 – 4a + 7ab -3b-12

= (12 – 4)a – (9 – 7)ab + (5 – 3)b – 3 – 12

= 8a – 2ab + 2b – 15

**8. If we multiply 5x and (– 4xyz), then we get:**

A. 20x^{2}yz

B. -20x^{2}yz

C. x^{2}yz

D. -2xyz

Answer: **B**

Explanation: (5x) x (-4xyz)

= 5 × x × (-4) × x × y × z

= -20x^{1+1}yz

= -20x^{2}yz

**9. The product of 4x and 0 is:**

A. 4x

B. 4

C. 0

D. None of the above

Answer: **C**

Explanation: Any value multiplied by zero is zero.

**10. The volume of a cuboid with length, breadth and height as 5x, 3x ^{2} and 7x^{4} respectively is:**

A. 105x^{7}

B. 105x^{2}

C. 105x^{4}

D. 105x

Answer: **A**

Explanation: Volume of cuboid = Length × breadth × height

V = 5x × 3x^{2} × 7x^{4}

V = 105 x^{1+2+4}

V = 105x^{7} cubic units

**11. The product of 5x and 3y is:**

A. xy

B. 2xy

C. 5xy

D. 15xy

Answer: (D) 15xy

(5x)(3y) = 15xy

**12. The product of 6x and -11x is:**

A. 66x²

B. -66x²

C. x²

D. -x²

Answer: B. -66x²

(6x) (-11x) = –66x²

**13. The area of a rectangle whose length and breadth are 3y and 9y² respectively is:**

A. 12y³

B. 21y³

C. 27y³

D. y³

Answer: C. 27y³

Explanation:

Area of rectangle = length x breadth = 3y x 9y² = 27y³.

**14. The area of a rectangle that has length = 2a²b and breadth = 3ab² is:**

A. 6a³b³

B. a³b³

C. 2a³b³

D. 4a³b³

Answer: A. 6a³b³

Explanation:

Area of rectangle = (2a²b)(3ab²) = 6a³b³

**15. The side of a cube is 2a. Find the volume of the cube.**

A. 4a²

B. 2a

C. 8a³

D. 8

Answer: C. 8a³

Explanation:

Volume of the cube = 2a × 2a × 2a = 8a³

**16. Multiplication of monomials x², (–x)³, (–x) ^{4} is equal to:**

A. x^{9}

B. x^{5}

C. x^{7}

D. x^{6}

Answer: A. x^{9}

Explanation:

(x²).(-x³).(-x)^{4} = x^{9}

**17. The value of (x – y)(x + y) + (y – z)(y + z) + (z – x) (z + x) is:**

A. x + y + z

B. x² + y² + z²

C. xy + yz + zx

D. 0

Answer: D. 0

Explanation:

(x – y)(x + y) + (y – z)(y + z) + (z – x) (z + x)

= x² – y² + y² – z² + z² – x² [By algebraic identity: a^{2} – b^{2} = (a+b) (a-b)]

= 0

**18. (a – b)² is equal to:**

A. a² + b² – 2ab

B. a² + b² + 2ab

C. a² + b²

D. 2ab

Answer: A. a² + b² – 2ab

Explanation: By algebraic identity,

(a + b)² = a² + b² – 2 ab

**19. The product of 3xy ^{2}z and 4x is:**

A. 12xyz

B. 12xy^{2}

C. 12x^{2}y^{2}z

D. 12x^{2}yz

Answer: C. 12x^{2}y^{2}z

Explanation: The product of 3xy^{2}z and 4x is:

⇒ (3xy^{2}z) (4x)

⇒ 3.x.y^{2}.z.4.x

⇒ 12x^{2}y^{2}z

**20. Which of the following is a like term as 8xy?**

A. 8

B. 8x

C. 8y

D. xy

Answer: D. xy