ab(a+b) + bc(b+c) + ca(c+a) = a^2b + ab^2 + b^2c + bc^2 + ca(c+a) + 2abc 
= ab^2 + b^2c + a^2b + bc^2 + 2abc + ca(c+a) 
=b^2(a+c) + b(a^2 + c^2 + 2ac) + ca(c+a) 
=b^2(a+c) + b(a+c)^2 + ca(c+a) 
=(c+a)[b^2 + b(a+c) + ca] 
=(c+a)[b^2 + ab + bc + ca] 
=(c+a)[b(b+a) + c(b+a)] 
=(c+a)(b+c)(b+a) 

\(ab\left(a+b\right)+bc\left(b+c\right)+ca\left(c+a\right)+2abc\)

\(=ab\left(a+b\right)+abc+bc\left(b+c\right)+abc+ca\left(c+a\right)\)

\(=ab\left(a+b+c\right)+bc\left(b+c+a\right)+ca\left(c+a\right)\)

\(=\left(a+b+c\right)\left(ab+bc\right)+ca\left(c+a\right)\)

\(=b.\left(a+b+c\right)\left(a+c\right)+ca\left(c+a\right)\)

\(=\left(a+c\right)\left[b.\left(a+b+c\right)+ca\right]\)

\(=\left(a+c\right)\left(ab+b^2+bc+ca\right)\)

\(=\left(a+c\right)\left[a\left(b+c\right)+b\left(b+c\right)\right]\)

\(=\left(a+c\right)\left(b+c\right)\left(a+b\right)\)

\(ab\left(a+b\right)+bc\left(b+c\right)+ca\left(c+a\right)+3abc\)

\(=ab\left(a+b\right)+abc+bc\left(b+c\right)+abc+ca\left(c+a\right)+abc\)

\(=ab\left(a+b+c\right)+bc\left(b+c+a\right)+ca\left(c+a+b\right)\)

\(=\left(a+b+c\right)\left(ab+bc+ac\right)\)

Tham khảo nhé~

thank you

\(T=a^2b+ab^2+b^2c+bc^2+c^2a+ca^2+abc+abc\)

\(T=a^2b+ab^2+abc+b^2c+bc^2+abc+c^2a+a^2c\)

\(T=ab\left(a+b+c\right)+bc\left(a+b+c\right)+ac\left(a+c\right)\)

\(T=\left(a+b+c\right)\left(b\left(a+c\right)\right)+ac\left(a+c\right)\)

\(T=\left(a+c\right)\left(b\left(a+b+c\right)+ac\right)\)

=(a+b-c)(b+c-a)(a+c-b)

d) (b+c)(b+a)(c-a)

c) (b-1)(ac+1-a-c)

thông cảm 2 câu đầu chưa nghĩ ra 

cho mình k mình giúp

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