Question

what is the formula of (a-b)³

Answer 1

acube-3ab(a-b)-bcube
Hope it helps..

Answer 2

Answer:

(a-b)³ = a³-3a²b+3ab²-b³

Or

(a-b)³ = a³-b³-3ab(a-b)

Explanation:

(a-b)³

= (a-b)(a-b)²

= (a-b)(a²-2ab+b²)

= a(a²-2ab+b²)-b(a²-2ab+b²)

= a³-2a²b+ab²-a²b+2ab²-b³

= a³-3a²b+3ab²-b³

Or

= a³-b³-3a²b+3ab²

= a³-b³-3ab(a-b)

Therefore,

(a-b)³ = a³-3a²b+3ab²-b³

Or

(a-b)³ = a³-b³-3ab(a-b)

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