CBSE Class 8 Mathematics Algebraic Expressions and Identities MCQs

Question:

a) 152

b) 150

c) 148

d) none

Answer: 152

Question:

a) a + b + c

b) none

c) 0

d) 1

Answer: a + b + c

Question: The value of (x + 3)³ – (x – 3)³ is

a) 18x² + 54

b) 1 – x³

c) 0

d) 3x² – 5

Answer: 18x² + 54

Question: The value of 25x² + 16y² + 40xy at x = 1 and y = –1 is

a) 1

b) 81

c) – 48

d) none

Answer: 1

Question:

a) – 2xy

b) – 12xy

c) 2 xy

d) 12 xy

Answer: – 2xy

Question:

a) 9

b) 1.176

c) 6.66

d) none

Answer: 9

Question:

a) 8

b) 4

c) 2

d) 6

Answer: 8

Question:

a) 9

b)

c) Both

d) None of these

Answer: 9

Question: If 3x – 7y = 10 and xy = – 1 then the value of 9x² + 49y² is

a) 58

b) 14/2

c) 104

d) – 104

Answer: 58

Question:

a) 32

b) 136

c) 64

d) 68

Answer: 32

Question:

a) 316

b) 361

c) – 188

d) none

Answer: 316

Question:

a)

b)

c)

d) 0

Answer:

Question: (3x – 5y)³ – (5x – 2y)³ + (2x + 3y)³

a) – 3 (3x – 5y) (2x – 5y) (2x + 3y)

b) 3(3x – 5y) (5x – 2y) ( 2x + 3y)

c) (3x – 5y) (2y – 5x) (2x + 3y)

d) (3x – 5y) (5x – 2y) (2x + 3y)

Answer: – 3 (3x – 5y) (2x – 5y) (2x + 3y)

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

a) 27

b) 29

c) 729

d) 495

Answer: 27

Question: If x³ + y³ + z³ = 3xyz then the relation between x, y and z is

a) either x + y + z = 0 (or) x = y = z

b) x + y + z = 0

c) x = y = z

d) neither x + y + z = 0 nor x = y = z

Answer: either x + y + z = 0 (or) x = y = z

Question: The equality b² + 5 > 9b + 12 us satisfied if

a) b > 9 (or) b < 0

b) b > 8 (or) b < 0

c) b > 9 (or) b < 1

d) b = 10 (or) b = – 1

Answer: b > 9 (or) b < 0

Question:

a) greater than 2

b) grater than 4

c) less than 2

d) less than 4

Answer: greater than 2

Question:

a) 100

b) 1

c) 10

d) none

Answer: 100

Question:

a) 1

b) ½

c) 0

d) none

Answer: 1

Question:

a) 0.1

b) 0.04

c) 0

d) 0.2

Answer: 0.1

Question: If 2x + y = 5 then 4x + 2y is equal to

a) 10

b) 8

c) 5

d) 9

Answer: 10

Question: If x + y = 6 and 3x – y = 4 then x – y is equal to

a) – 1

b) 2

c) 0

d) 4

Answer: – 1

Question: If the product of two numbers is 10 and the sum is 7, then the larger of the two numbers is

a) 5

b) – 2

c) 2

d) None of these

Answer: 5

Question: The value of (55)³ – (75)³ + (20)³ is

a) – 247500

b) 125320

c) 251750

d) none

Answer: – 247500