Question

Evalutale
(3x-2) power3​

Answer 1

Evaluating (3x - 2)³

Now,

We can use the algebraic identity

• (a - b)³ = a³ - b³ - 3ab(a - b)

OR  

• (a - b)³ = a³ - b³ - 3a²b + 3ab²

By using this

(a - b)³ = a³ - b³ - 3ab(a - b)

We get (a = 3x) and (b = 2)

(3x - 2)³ = (3x)³ - (2)³ - 3(3x)(2)[3x - 2]

            = 27x³ - 8 - 18x(3x -2)

            = 27x³ - 8 - 54x² + 36x

            = 27x³ - 54x² + 36x - 8

Now,

By another

• (a - b)³ = a³ - b³ - 3a²b + 3ab²

(3x - 2)³ = (3x)³ - (2)³ - 3(3x)²(2) + 3(3x)(2)²

             = 27x³ - 8 - 54x² + 36x

             = 27x³ - 54x² + 36x - 8

So,

$\boxed{(3x-2)=27x^{3} - 54x^{2} + 36x - 8}$

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More Identities

• (a ± b)² = a² + b² ± 2ab
• (a + b)² - (a - b)² = 4ab
• (a² - b²) = (a + b)(a - b)
• (a ± b)³ = (a ± b)(a² + b² ± ab)