Ta có (x^2 + y^2 )^3 + (z^2 – x^2 )^3 – (y^2 + z^2 )^3

= (x^2 + y^2 )^3 + (z^2 – x^2 )^3 + (-y^2 - z^2 )^3

Ta thấy x^2 + y^2 + z^2 – x^2 – y^2 – z^2 = 0

=> áp dụng nhận xét ta có: (x^2+y^2 )^3+ (z^2 -x^2 )^3 -y^2 -z^2 )^3

=3(x^2 + y^2 ) (z^2 –x^2 ) (-y^2 – z^2 )

= 3(x^2+y^2 ) (x+z)(x-z)(y^2+z^2 )

\((x^2+y^2)^3+(z^2-x^2)^3-(y^2+z^2)^3\)

\(=-3[x^4y^2-x^4z^2-x^2y^2z^2+x^2z^4-x^2y^4+x^2y^2z^2+y^4z^2-y^2z^4\)

\(=-3[x^2(x^2y^2-x^2z^2-z^2y^2+z^4)-y^2(x^2y^2-x^2z^2-z^2y^2+z^4)\)

\(=-3(x^2-y^2)(x^2y^2-x^2z^2-z^2y^2+z^4)\)

\(=-3(x^2-y^2[x^2(y^2-z^2)-z^2(y^2-z^2)]\)

\(=-3(x^2-y^2)(x^2-z^2)(y^2-z^2)\)

\(=-3(x-y)(x+y)(x-z)(x+z)(y+z)(y-z)\)

1 + 16 + 2 + 5 + 6

= 17 + 7 + 6

= 17 + 13

= 30

giang thuy

 100000000000 chia hết cho chính nó , chia cho 5 , chia cho 2 , chia 10 , chia 100 vv

Dễ ẸC 

\(\text{100000000000}:\text{100000000000}=0\)

IQ 1000000000000000000000000000000000000000000000000000000000000 là tui ^^

ok file

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TL:

Đặt A=(3+1)(32+1)(34+1)(38+1)(316+1)(332+1)A=(3+1)(32+1)(34+1)(38+1)(316+1)(332+1)

⇒2A=(3−1)(3+1)(32+1)(34+1)(38+1)(316+1)(332+1)⇒2A=(3−1)(3+1)(32+1)(34+1)(38+1)(316+1)(332+1)

=(32−1)(32+1)(34+1)(38+1)(316+1)(332+1)=(32−1)(32+1)(34+1)(38+1)(316+1)(332+1)

=...........................................=...........................................

=(332−1)(332+1)=364−1=(332−1)(332+1)=364−1

⇒A=364−122

k cho mk nha

HT