Students must solve the important Class 8 Maths MCQ Questions of Algebraic Expressions and Identities with Answers. This will help them to keep up with what is being taught in class and what might appear in the exams. A significant chunk of questions from this subject comes within the type of MCQ Questions. Therefore, by practicing more objective-type questions, the students will ensure securing better marks from this chapter.

MCQ Questions for class 8 Maths allow the students to study in-depth and prepare well in advance. They contain only the questions which are most likely to appear in the examinations. These questions are carefully curated based on the current syllabus, and curriculum, previous year questions papers.

Practice the MCQ Questions for Class 8 Algebraic Expressions and Identities with answers which are given here. 

Practice MCQ Question for Class 8 Maths chapter-wise

1. The expression x + 3 is in

(a) one variable
(b) two variables
(c) no variable
(d) none of these

2. The value of the expression x³ + y³ when x=2 and y=-2 is 

(a) 0
(b) 8
(c) 16
(d) -16

3. The expression 4xy + 7 is in

(a) one variable
(b) two variables
(c) no variable
(d) none of these

4. The value of 5x when x = 5 is

(a) 5
(b) 10
(c) 25
(d) -5

5. The value of x² – 2x + 1 when x = 1 is

(a) 1
(b) 2
(c) -2
(d) 0

6. The value of x² + y² when x = 1, y = 2 is

(a) 1
(b)2
(c) 4
(d) 5

7. The sum of 7x, 10x and 12x is

(a) 17x
(b) 22x
(c) 19x
(d) 29x

8. The sum of 8pq and -17 pq is

(a) pq
(b) 9pq
(c) -9pq
(d) -pq

9. The sum of 5x², -7x², 8x², 11x² and -9x² is

(a) 2x²
(b) 4x²
(c) 6x²
(d) 8x²

10. The result of subtraction of 3x from -4x is

(a) -7x
(b) 7x
(c) x
(d) -x

11. The product of 7x and -12x is

(a) 84x²
(b) -84x²
(c) x²
(d) -x²

12. The area of a rectangle whose length and breadth are 9y and 4y² respectively is

(a) 4y³
(b) 9y³
(c) 36y³
(d) 13y³

13. The volume of a cube of side 2a is

(a) 4a²
(b) 2a
(c) 8a³
(d) 8

14. The algebraic expression 3x + 2y + 6 is

(a) monomial
(b) Binomial
(c) Trinomial
(d) None of the above

15. 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

16. 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

17. The volume of a rectangle with length, breadth and height as 5x, 3x² and 7x⁴ respectively is:

(a) 105x⁷
(b) 105x²
(c) 105x⁴
(d) 105x

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

(a) 6a³b³
(b) a³b³
(c) 8a³b³
(d) 6a³b⁰

19. Expressions consists of _____________ and _______________.

(a) variables, constants
(b) identities
(c) expressions
(d) none of these

20. An algebraic expression consisting of three terms is called a ______ expression.

(a) monomial
(b) trinomial
(c) binomial
(d) polynomial

21. Value of expression a(a²+a +1)+5 for ‘ a’ = 0 is

(a) a+5      
(b) 1
(c) 6
(d) 5

22. Identify the coefficient of xy² in xy – 4xy² – 5x²y

(a) -5      
(b) 5
(c) -4
(d) 4

23. Obtain the volume of rectangle boxes with length, breadth and height are. 6a, 3b², 7a⁴

(a) 15a³ b⁵   
(b)  216 b³
(c) 126 a⁵ b²
(d) 17a² b³

24. Which of the following is like term as 7xy?

(a) 9
(b) 9x
(c) 9y
(d) 9xy

25. If a + b + c = 9 and ab + bc + ca = 26, then the value of a³ + b³ + c³ – 3abc

(a) 27
(b) 29
(c) 729
(d) 495

Answer:

1. Answer: (a) one variable

Explanation:  The only variable is x.

2. Answer: (a) 0

Explanation:  Value of x³+y³

=(2)³+(−2)³

=8−8

=0

3. Answer:(b) two variables

Explanation:  There are two variables x and y.

4. Answer: (c) 25

Explanation:  Value = 5 × 5 

= 25.

5. Answer: (d) 0

Explanation:  Value = (1)² – 2(1) + 1 

= 0

6. Answer: (d) 5

Explanation:  Value = (1)² + (2)² 

= 5.

7. Answer: (d) 29x

Explanation:  Sum = (7 + 10 + 12)x 

= 29x

8. Answer: (c) -9pq

Explanation:  Sum = {8 + (-17)} pq 

= -9pq

9. Answer: (d) 8x²

Explanation:  Sum = {5 + (-7) + 8 + 11 + (-9)} x²

 = 8x²

10. Answer: (a) -7x

Explanation:  -4x -3x 

= -7x

11. Answer: (b) -84x²

Explanation:  (7x) (-12x) 

= – 84x²

12. Answer: (c) 36y³

Explanation: Area of rectangle = l x b

= (9y)(4y²) 

= 36y³

13. Answer: (c) 8a³

Explanation: Volume = 2a × 2a × 2a

= 8a³

14. Answer: (c) Trinomial

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

15. Answer: (a) 5xy + 9yz + 3zx + 5x – 4y

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

= 5y + 9yz + 3zx + 5x – 4y

16. Answer: (c) 8a – 2ab + 2b – 15

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

17. Answer: (a) 105x⁷

Explanation:  Volume of rectangle = Length × breadth × height

V = 5x × 3x² × 7x⁴

V = 105 x¹⁺²⁺⁴

V = 105x⁷ cubic unit.

18. Answer: (a) 6a³b³

Explanation:  Area of rectangle (l x b)

= (2a²b)(3ab²) 

= 6a³b³

19. Answer: (a) variables, constants

Explanation: An expression is a combination of operators, constants and variables. An expression may consist of one or more operands, and zero or more operators to produce a value.

20. Answer: (b) trinomial

Explanation:  An algebraic Expression containing one term is monomial.

An algebraic Expression containing two terms is binomial.

An algebraic Expression containing three terms is trinomial.

21. Answer: (d) 5

Explanation: a(a²+a+1)+5

=a³+a²+a+5

Putting the value of a,we get,

a³+a²+a+5

=0+0+0+5

= 5

22. Answer: (c) -4

Explanation:  xy – 4xy² – 5x²y = 0

= (-4) xy² 

= Coefficient (-4)

23. Answer: (c)  126 a⁵ b²

Explanation: 6a × 3b² × 7a²

= 6 × a × 3 × b × b × 7 × a × a

= 126 a⁵ b²

24. Answer: (d) 9xy

Explanation: The terms which have the same literal coefficients raised to the same powers but may only differ in numerical coefficient are like terms.

25. Answer: (a) 27

Explanation: ⇒ (a + b + c)² = 81 [On squaring both sides of (i)]  

⇒ a² + b² + c² + 2(ab + bc + ac) = 81  

⇒ a² + b² + c² + 2 × 26 = 81 [∵ab + bc + ac = 26]  

⇒ a² + b² + c² = (81 - 52)  

⇒ a² + b² + 2 = 29.  

Now, we have 

a³ + b³ + c³ - 3abc = (a + b + c) (a² + b² + c² - ab - bc - ac)   

= (a + b + c) [(a² + b² + c² ) - (ab + bc + ac)]   

= 9 × [(29 - 26)]   

= (9 × 3)   

= 27

Click here Practice MCQ Question for Algebraic Expressions and Identities Class 8