pham tich da thuc thanh nhan tu
(a+b+c)3- (a+b-c)3- (b+c-a)3- (c+a-b)3
Những câu hỏi liên quan
a^3(b-c)+ b^3(c-a)+c^3(a-b) phan tich da thuc thanh nhan tu
phan tich da thuc thanh nhan tu a(b^3-c^3)+b(c^3-a^3)+c(a^3-b^3)
\(a\left(b^3-c^3\right)+b\left(c^3-a^3\right)+c\left(a^3-b^3\right)\)
\(=a\left(b^3-c^3\right)-b\left(a^3-c^3\right)+c\left(a^3-b^3\right)\)
\(=a\left(b^3-c^3\right)-b\left[\left(a^3-b^3\right)+\left(b^3-c^3\right)\right]+c\left(a^3-b^3\right)\)
\(=a\left(b^3-c^3\right)-b\left(b^3-c^3\right)-b\left(a^3-b^3\right)+c\left(a^3-b^3\right)\)
\(=\left(b^3-c^3\right)\left(a-b\right)-\left(a^3-b^3\right)\left(b-c\right)\)
\(=\left(b-c\right)\left(b^2+bc+c^2\right)\left(a-b\right)-\left(a-b\right)\left(a^2+ab+b^2\right)\left(b-c\right)\)
\(=\left(a-b\right)\left(b-c\right)\left[\left(b^2+bc+c^2\right)-\left(a^2+ab+b^2\right)\right]\)
\(=\left(a-b\right)\left(b-c\right)\left(bc+c^2-a^2-ab\right)\)
\(=\left(a-b\right)\left(b-c\right)\left[b\left(c-a\right)+\left(c-a\right)\left(c+a\right)\right]\)
\(=\left(a-b\right)\left(b-c\right)\left(c-a\right)\left(a+b+c\right)\)
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a(b3−c3)+b(c3−a3)+c(a3−b3)
=a(b3−c3)−b(a3−c3)+c(a3−b3)
=a(b3−c3)−b[(a3−b3)+(b3−c3)]+c(a3−b3)
=a(b3−c3)−b(b3−c3)−b(a3−b3)+c(a3−b3)
=(b3−c3)(a−b)−(a3−b3)(b−c)
=(b−c)(b2+bc+c2)(a−b)−(a−b)(a2+ab+b2)(b−c)
=(a−b)(b−c)[(b2+bc+c2)−(a2+ab+b2)]
=(a−b)(b−c)(bc+c2−a2−ab)
=(a−b)(b−c)[b(c−a)+(c−a)(c+a)]
=(a−b)(b−c)(c−a)(a+b+c)
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phan tich da thuc thanh nhan tu a(b^3-c^3)+b(c^3-a^3)+c(a^3-b^3)
phan tich da thuc thanh nhan tu a(b^2+c^2)+b(c^2+a^2)+c(a^2+b^2)-2abc-a^3-b^3-c^3.
phan tich da thuc thanh nhan tu
\(\left(\text{a}+b+c\right)^3-\text{a}^3-b^3-c^3\)
\(\left(a+b+c\right)^3-a^3-b^3-c^3\)
\(=\left[\left(a+b\right)+c\right]^3-a^3-b^3-c^3\)
\(=\left(a+b\right)^3+3\left(a+b\right)^2c+3\left(a+b\right)c^2+c^3-a^3-b^3-c^3\)
\(=a^3+b^3+3a^2b+3ab^2+3c\left(a^2+2ab+b^2\right)+3ac^2+3bc^2-a^3-b^3\)
\(=3a^2b+3ab^2+3a^2c+6abc+3b^2c+3ac^2+3bc^2\)
\(=3\left(a^2b+ab^2+a^2c+ac^2+2abc+b^2c+bc^2\right)\)
\(=3\left(a^2b+ab^2+a^2c+ac^2+abc+abc+b^2c+bc^2\right)\)
\(=3\left[ab\left(a+b\right)+c^2\left(a+b\right)+ac\left(a+b\right)+bc\left(a+b\right)\right]\)
\(=3\left(a+b\right)\left(ab+c^2+ac+bc\right)\)
\(=3\left(a+b\right)\left[c\left(a+c\right)+b\left(a+c\right)\right]\)
\(=3\left(a+b\right)\left(a+c\right)\left(b+c\right)\)
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Phan tich da thuc thanh nhan tu
\(\left(a-b\right)^3+\left(b-c\right)^3+\left(c-a\right)^3\)
(a−b)3+(b−c)3+(c−a)3=3(a−b)(b−c)(c−a)
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Xem thêm câu trả lời
phan tich da thuc thanh nhan tu a3(b2-c2)+b3(c2-a2) + c3(a2-b2)
phan tich da thuc thanh nhan tu
a3+b3+c3-3abc
a3 + b3 + c3 - 3abc
= (a3 + 3a2b + 3ab2 + b3 ) + c3 - 3abc - 3a2b - 3ab2
=[(a+b)3 + c3 ]- (3abc+3a2b+3ab2)
=(a+b+c)[(a+b)2 - (a+b)c + c2 ] - 3ab(c+a+b)
=(a+b+c)(a2+2ab+b2-ac-bc+c2)-3ab(a+b+c)
=(a+b+c)(a2+2ab+b2-ac-bc+c2-3ab)
=(a+b+c)(a2+b2+c2-ab-bc-ca)
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phan tich da thuc sau thanh nhan tu : ab(a-b)+bc(b-c)+ca(c-a)
ab(a-b)+bc(b-c)+ac(c-a)
=ab(a-b)-bc[(a-b)+(c-a)] +ac(c-a)
=ab(a-b) -bc(a-b) -bc(c-a) + ac(c-a)
=b(a-c)(a-b) -c(a-c)(a-b)
=(b-c)(a-c)(a-b)
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