Question

efetue o cubo (ab + 2bc)³

Answer 1

(ab + 2bc)³=

(ab + 2bc).(ab + 2bc).(ab + 2bc)=

(a²b² + 4ab²c + 4b²c²). (ab +2bc)=

a³b³ + 4a³b³c + 4ab³c² + 2a²b³c + 8ab³c² + 8b³c³

Answer 2

$(ab+2bc)^3 =(ab+2bc)(ab+2bc)(ab+2bc)=$
$[(ab)^2+4acb^2+4ab^2c^2](ab+2bc)]=$
$(ab)^3+4a^2b^3c+4ab^3c^2+2a^2b^3c+8ab^3c^2+(2bc)^3=$
$(ab)^3+6a^2b^3c+12ab^3c^2+(2bc)^3$