Verified answer

0.064-0.4х-х²+х³=(х³+0.064)-(х²+0.4х)=

(х³+0.4³)-х(х+0.4)=

(х+0.4)(х²-0.4х+0.16)-х(х+0.4)=

(х+0.4)(х²-1.4х+0.16)

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формула суммы кубов

а³+b³=(a+b)(a²-ab+b²)