Class 8 - Mathematics
Algebraic Expressions and Identities - Exercise 9.3
Top Block 1
1. Carry out the multiplication of the expressions in each of the following pairs:
(i) 4p, q + r
(ii) ab, a – b
(iii) a + b, 7a²b² (iv) a² – 9, 4a
(v) pq + qr + rp, 0
(i) 4p, q + r
(ii) ab, a – b
(iii) a + b, 7a²b² (iv) a² – 9, 4a
(v) pq + qr + rp, 0
Answer :
2. Complete the table:
| First Expression | Second Expression | Product | |
|---|---|---|---|
| 1. | a | b + c + d | ….. |
| 2. | x + y – 5 | 5xy | ….. |
| 3. | p | 6p²-7p + 5 | ….. |
| 4. | 4p²q² | p² – q² | ….. |
| 5. | a + b + c | abc | ….. |
Answer :
| First Expression | Second Expression | Product | |
|---|---|---|---|
| 1. | a | b + c + d |  |
| 2. | x + y – 5 | 5xy |  |
| 3. | p | 6p²-7p + 5 |  |
| 4. | 4p²q² | p² – q² |  |
| 5. | a + b + c | abc |  |
3. Find the product:
Mddle block 1
Answer :
4. (a) Simplify: 3x(4x – 5) + 3 and find values for
(i) x = 3
(ii) x = ½
(b) Simplify: a(a² + a + 1) + 5 and find its value for
(i) a = 0
(ii) a = 1
(iii) a = -1
(i) x = 3
(ii) x = ½
(b) Simplify: a(a² + a + 1) + 5 and find its value for
(i) a = 0
(ii) a = 1
(iii) a = -1
Answer :
5. (a) Add:p(p – q), q(q – r) and r(r – p)
(b) Add: 2x(z – x – y) and 2y(z – y – zx)
(c) Subtract: 3𝓁(𝓁 – 4𝓂 + 5&nscr) from 4𝓁(10𝓃 – 3𝓂 + 2𝓁)
(d) Subtract: 3a(a + b + c) – 2b(a – b + c) from 4c(-a + b + c)
(b) Add: 2x(z – x – y) and 2y(z – y – zx)
(c) Subtract: 3𝓁(𝓁 – 4𝓂 + 5&nscr) from 4𝓁(10𝓃 – 3𝓂 + 2𝓁)
(d) Subtract: 3a(a + b + c) – 2b(a – b + c) from 4c(-a + b + c)
Answer :
