Grade 8 Algebraic Expressions and Identities Worksheets -CoolGyan

Grade 8 Maths Algebraic Expressions and Identities Multiple Choice Questions (MCQs)

1. What are the co-efficients of y in the expression yz² + 5?
(a) 5
(b) z
(c) z²
(d) None of these
2. The constant term in the expression 1 + x² + x is
(a) 1
(b) 2
(c) x
(d) x²
3. The expression x + y – xy is:
(a) Monomial
(b) Binomial
(c) Trinomial
(d) Quadrinomial
4. From the following expressions 3ab, a², b², a, 5ab, -2ab, 2a² the three like terms are:
(a) 3ab, 5ab, -2ab
(b) a², a, 2a²
(c) 3ab, a², b²
(d) 2a², a², a
5. The value of expression 5n – 2, when n = -2 is:
(a) -12
(b) 8
(c) 1
(d) -8
6. If the length of each side of the equilateral triangle is l, then the perimeter of the equilateral triangle is:
(a) 3l
(b) 3 + 1
(c) 3 – l
(d) $frac{l}{3}$
7. Which of the following is trinomial:
(a) 2a + 6b – 1
(b) 1
(c) 5a – 7
(d) a + b + c – 3
8. The value of expression 5n² + 5n – 2 for n = -2 is
(a) 13
(b) 3
(c) 8
(d) 12
9. The expression for the statement: ‘y multiplied by 10 and then 7 added to product.
(a) 10 + y + 7
(b) 7y + 10
(c) 10y + 7
(d) 10y
10. The numerical co-efficient of y in the expression 2x + 3y + 7z is:
(a) 2
(b) 3
(c) 7
(d) 3y
11. ‘2’ is common factor of the expressions:
(a) 12a² b, 15ab²
(b) 5xy, 10x
(c) 10x², -18x³, 14x⁴
(d) 33y, -22z
12. The area of a rectangle is ‘xy’ where V is length and ly’ is breadth. If the length of rectangle is increased by 5 units and breadth is decreased by 3 units, the new area of rectangle will be:
(a) (x – y)(x + 3)
(b) xy + 15
(c) (x + 5)(y – 3)
(d) xy + 5 – 3
13. The product of a², 2a², 5a¹⁰ is
(a) 10 a¹⁴
(b) 7 a¹⁴
(c) 10 a²²
(d) 10 a⁴⁰
14. Which of the following expression is trinomial:
(a) xyz
(b) xy + z
(c) x + y + z
(d) x + yz
15. Value of expression a(a² + a + 1) + 5 for ‘ a’ = 0 is:
(a) a + 5
(b) 1
(c) 6
(d) 5
16. Evalute (4x + y)² by suitable identity:
(a) 4x² + y² + 8x
(b) 4x + y + 8xy
(c) 16x² + y² + 8xy
(d) 16x² + y² + 8
17. (a – b)² is equal to:
(a) a² + b² – 2ab
(b) a² – b² + 2ab
(c) a² – b²
(d) (a – b)(a + b)
18. If ab = 6 and a + b = 5 then the value of (a² + b²) is:
(a) 11
(b) 12
(c) 13
(d) 16
19. If x – y = 7 and xy = 9, then the value of (x² + y²) is:
(a) 64
(b) 67
(c) 63
(d) None of these
20. If $left(x+frac{1}{x} ight)$ = 4, then the value of $left(x^{2}+frac{1}{x^{2}} ight)$ is:
(a) 14
(b) 12
(c) 16
(d) None of these

Class 8 Maths Algebraic Expressions and Identities Fill In The Blanks

1. The number of terms in the product of (3x² + 6xy + 5y²) and (3x + 4y – 13) is ……………….. .
2. In the product of (4a³ + 5a² – 11a) and (-15 + 3a – 7a²), the co-efficient of a⁴ is …………………… .
3. The value of (3a – 4b + 2) × (5a + 6) for a = 1 and b = -2 is ……………… .
4. The value of is ………………. .
5. Find the product: (A + B).(A – B).(A² + B²).(A⁴ + B⁴) = ………………….. .

Class 8 Maths Algebraic Expressions and Identities True(T) Or False(F)

1. If, a + $frac{1}{a}$ = 7, then a² + $frac{1}{a^{2}}$ = 49
2. The product of a binomial and a trinomial will always have 5 terms.
3. (3x² + 5y²) × (5x⁵ + 8y³) = 15x⁷ + 24x²y³ + 25x⁵y² + 40y⁵

Class 8 Maths Algebraic Expressions and Identities Very Short Answer Type Questions

1. What are the co-efficients of y in the expression 4x – 3 y?
2. What is the statement for the expression 3mn + 5
3. What is the numerical co-efficient of y² in the expression 2x²y – 15xy² + 7y
4. What must be subtracted from 2a + b to get 2a – b.
5. What must be added to 3x + y to get 2x + 3y?
6. What should be value of ‘a’ if y² + y – a equals to 3 for y = 1?

Class 8 Maths Algebraic Expressions and Identities Short Answer Type Questions

1. What must be added to 7z³ – 11z² – 129 to get 5z² + 7z – 92 ?
2. If (3x – 5y) = 10 and xy=5, then find the value of 9x² + 25y².
3. If x + y = 9 and xy= 14, find x² – y².
4. If 3x + 2y = 12 and xy = 6, find the value of 9x² + 4y².

Class 8 Maths Algebraic Expressions and Identities Long Answer Type Questions

1. Given (x² + y²) = 74 and xy = 35, find the value of x + y and x – y.
2. If x + $frac{1}{x}$ = 4, find the value of
3. Using suitable identities evaluate the following:
(i) (93)²
(ii) (12.5)² – (7.5)²
(iii) 93 × 109

Grade 8 Algebraic Expressions and Identities Worksheets