Question

$( {a}^{3} - {b}^{3} ) + ( {3a}^{3} + {2a}^{2}b - {b}^{2} + {2b}^{3})$
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Answer 1

Step-by-step explanation:

(a³-b³)+(3a³+2a²b-b²+2b³)

= a³+3a³-b³+2b³+2a²b-b²

= 4a³+b³+2a²b-b²

= 2a²( 2a+b) +b²( b-1)