Question

viet cac bieu thuc sau duoi dang tich:
a,1,24\(^3\)-0,24\(^3\)

b,(a-1)\(^3\)+(a+1)\(^3\)

c, a\(^6\)-b\(^6\)

Answer 1

Câu a : \(1,24^3-0,24^3=\left(1,24-0,24\right)\left(1,24^2+1,24.0,24+0,24^2\right)=1.\left(1,5376+0,2976+0,0576\right)\)

Câu b : \(\left(a-1\right)^3+\left(a+1\right)^3=\left(a-1+a+1\right)\left[\left(a-1\right)^2-\left(a-1\right)\left(a+1\right)+\left(a+1\right)^2\right]=2a\left(a^2+3\right)\)

Câu c : \(a^6-b^6=\left(a^3\right)^2-\left(b^3\right)^2=\left(a^3-b^3\right)\left(a^3+b^3\right)=\left(a-b\right)\left(a+b\right)\left(a^2-ab+b^2\right)\left(a^2+ab+b^2\right)\)

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