Chapter 9- Algebraic Expressions and Identities

Objective Questions (MCQ)

1. What kind of polynomial is -5abc?
   (a) Monomial
   (b) Binomial
   (c) Trinonial
   (d) None of the above
2. The value ofx² – 2yx + y² when x= 1; y = 2 is
   (a) 1
   (b) 2
   (c) 4
   (d) 5
3. Which of the following is a binomial?
   (a) 3xy
   (b) 41 + 5m
   (c) 2x + 3y-5
   (d) 4a – 7ab + 3b + 12
4. The sum of -7x, 3x and 11x
   (a) – 7x
   (b) 21x
   (c) 7x
   (d) -21x
5. What do you get when you subtract. -3xy from 5xy?
   (a) 3xy
   (b) 5xy
   (c) 8xy
   (d) 2xy
6. The volume of the cuboid of dimensions x, y, z is
   (a) x²y²z²
   (b) x³y³z³
   (c) xyz
   (d) x²y²z
7. The area of a rectangle with length 2l²m and breadth 31m² is
   (a) l³m³
   (b) 2l³m³
   (c) 4l³m³
   (d) 6l³m³
8. The value of (x + y) (x + y) + (y – z) (y + z) + (z – x) (z + x) is equal to
   (a) 3x²
   (b) 3y²
   (c) 3z²
   (d) 0
9. Which of the following is the numerical coefficient of x² y²?
   (a) 0
   (b) 1
   (c) x²
   (d) y²
10. Which of the following is the numerical coefficient of -5xy?
    (a) 2
    (b) x
    (c) 5
    (d) y

NCERT Solutions

Ex 9.1 Class 8 Maths Question 3.
11. Add the following:
(i) ab – bc, bc – ca, ca – ab
(ii) a – b + ab, b – c + bc, c – a + ac
(iii) 2p²q² – 3pq + 4, 5 + 7pq – 3p²q²
(iv) l² + m², m² + n², n² + l², 2lm + 2mn + 2nl

Ex 9.1 Class 8 Maths Question 4.

12. (a) Subtract 4a – 7ab + 3b + 12 from 12a – 9ab + 5b – 3
(6) Subtract 3xy + 5yz – 7zx from 5xy – 2yz – 2zx + 10xyz
(c) Subtract 4p²q – 3pq + 5pq² – 8p + 7q – 10 from 18 – 3p – 11q + 5pq – 2pq² + 5p²q

13. Identify the terms, their coefficients for each of the following expressions.
(i) 5xyz² – 3zy
(ii) 1 + x + x²
(iii) 4x²y² – 4x²y²z² + z²
(iv) 3 – pq + qr – rp
(v) x/2 + y/2 – xy
(vi) 0.3a – 0.6ab + 0.5b