Bọn óc chó, chúng mày đang coppy bài lớp 8 đấy :))
1. ( a + b + c )3 = a3 + b3 +c3 + 3( a + b )( b + c)( c + a )2. a3 + b3 + c3 – 3abc = ( a + b + c)(a2 + b2 + c2 – ab – bc – ca )3. ( a – b – c )2 = a2 + b2 + c2 – 2ab + 2bc – 2ca4. ( a + b + c )2 = a2 + b2 + c2 + 2ab + 2bc + 2ca5. ( a + b – c )2 = a2 + b2 + c2 + 2ab – 2bc – 2 ca
1. ( a + b + c )3 = a3 + b3 +c3 + 3( a + b )( b + c)( c + a )
2. a3 + b3 + c3 – 3abc = ( a + b + c)(a2 + b2 + c2 – ab – bc – ca )
3. ( a – b – c )2 = a2 + b2 + c2 – 2ab + 2bc – 2ca
4. ( a + b + c )2 = a2 + b2 + c2 + 2ab + 2bc + 2ca
5. ( a + b – c )2 = a2 + b2 + c2 + 2ab – 2bc – 2 ca.