Question

Cmr ( a+b)(a^2-ab+b^2)=a^3+b^3 (cm ngược nhé ! ) ?

Answer 1

\(\left(a+b\right)\left(a^2-ab+b^2\right)\)

\(=a^3-a^2b+ab^2+a^2b-ab^2+b^3\)

\(=a^3+b^3\)

Answer 2

Ta có:

\(VT=\left(a+b\right)\left(a^2-ab+b^2\right)\)

\(=a^3-a^2b+ab^2+ba^2-ab^2+b^3\)

\(=a^3+b^3\)

\(\Rightarrow VT=VP\)

\(\Rightarrow dpcm\)

Answer 3

Ta có : ( a + b )( a ² - ab + b² )

= a ³ - a² b + ab ² + a² b - ab² + b³

= a³ + b³

Answer 4

Ta có : (a + b)(a² - ab + b²)

= a³ - a²b + ab² + a²b - ab² + b³

= a³ + b³

Vậy (a + b)(a² - ab + b²) = a³ + b³

Answer 5

(a+b)(a^2-ab+b^2)=a^3+b^3

-> VT=(a+b)(a^2-ab+b^2)

=a^3-a^2b+ab^2+a^2b-ab^2+b^3

=a^3+(-a^2b+a^2b)+(ab^2-ab^2)+b^3

=a^3+0+0+b^3

=a^3+b^3=VP

->VT= VP(đpcm)

Answer 6

Ta có: (a+b)(a² -ab +b²) = a³ - a²b + ab² +a²b -ab² + b³

= a³ + b³

Vậy (a +b)(a²-ab+b²)= a³+b³