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

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

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

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

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

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

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

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

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

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

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

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

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

Tham khảo nhé~

thank you

      \(\left(x+2\right)\left(x+3\right)\left(x+4\right)\left(x+5\right)-24=0\)

\(\Rightarrow\left[\left(x+2\right)\left(x+5\right)\right]\left[\left(x+3\right)\left(x+4\right)\right]-24=0\)

\(\Rightarrow\left(x^2+7x+10\right)\left(x^2+7x+12\right)-24=0\)(1)

Đặt \(x^2+7x+11=t\)

Khi đó từ (1), ta được:

    \(\left(t-1\right)\left(t+1\right)-24=0\)

\(\Rightarrow t^2-25=0\)

\(\Rightarrow\left(t-5\right)\left(t+5\right)=0\)

\(\Rightarrow\left(x^2+7x+11-5\right)\left(x^2+7x+11+5\right)=0\)

\(\Rightarrow\left(x^2+7x+6\right)\left(x^2+7x+16\right)=0\)

\(\Rightarrow\left[x\left(x+1\right)+6\left(x+1\right)\right]\left[x^2+2.x.\frac{7}{2}+\frac{49}{4}+\frac{17}{4}\right]=0\)

\(\Rightarrow\left(x+1\right)\left(x+6\right)\left[\left(x+\frac{7}{2}\right)^2+\frac{17}{4}\right]=0\)

\(\Rightarrow\orbr{\begin{cases}x=-1\\x=-6\end{cases}}\)

giangtranthe601@gmail.com

23012004

=2(5x^2+2x-3

mik đã làm xog nh xin bạn hãy kiểm tra lại

em mình ko biết nên mình lên hỏi, bạn biết thì mình nghe theo, mình cảm ơn bạn nha