Question

solve pls maths chapter 2 polynomials class 9 ncert goa board

Answer 1

Step-by-step explanation:

1. Given: (2p-3q)³

using: (a-b)³=a³-b³-3ab(a-b).

=(2p)³- (3q)³- 3*2p*3q(2p-3q)

=8p³- 27q³- 18pq(2p-3q)

=8p³- 27q³- 36p²q + 54pq².

2. Given: (3b+2c)³

using: (a+b)³= a³+b³+3ab(a+b).

=(3b)³+ (2c)³+ 3*3b*2c(3b+2c)

=27b³ + 8c³ +18bc(3b+2c)

=27b³ + 8c³ + 54b²c +36bc².

3. Given:(3a-5b)³

using: (a-b)³=a³-b³-3ab(a-b).

=(3a)³- (5b)³- 3*3a*5b(3a-5b)

=27a³- 125b³- 45ab(3a-5b)

=27a³- 125b³- 135a²b + 225ab².

4. Given:(4a-6b)³

using: using: (a-b)³=a³-b³-3ab(a-b).

=(4a)³- (6b)³- 3*4a*6b(4a-6b)

=64a³- 216b³- 72ab(4a-6b)

=64a³- 216b³- 288a²b+ 432ab².