\(\left(x+1\right)\left(x+2\right)\left(x+3\right)\left(x+4\right)-24\\ =\left(x^2+5x+4\right)\left(x^2+5x+6\right)-24\\ =\left(x^2+5x+5-1\right)\left(x^2+5x+5+1\right)-24\\ =\left(x^2+5x+5\right)^2-1-24\\ =\left(x^2+5x+5\right)^2-25\\ =\left(x^2+5x\right)\left(x^2+5x+10\right)\)
Theo mk pai là trừ 24 nhé
Làm vài câu không thì mốc tường =))
Sửa đề:
\(\left(x+1\right)\left(x+2\right)\left(x+3\right)\left(x+4\right)-24\)
\(=\left[\left(x+1\right)\left(x+4\right)\right]\left[\left(x+2\right)\left(x+3\right)\right]-24\)
\(=\left(x^2+4x+x+4\right)\left(x^2+3x+2x+6\right)-24\)
\(=\left(x^2+5x+4\right)\left(x^2+5x+6\right)-24\) (1)
Đặt \(x^2+5x+4=t\Rightarrow x^2+5x+6=t+2\)
\(\Rightarrow\left(1\right)=t.\left(t+2\right)+24=t^2+2t-24\)
\(=t^2-4t+6t-24=t\left(t-4\right)+6\left(t-4\right)\)
\(=\left(t-4\right)\left(t+6\right)\) (*)
Thay \(t=x^2+5x+4\) vào (*) ta được:
\(\left(\text{*}\right)=\left(x^2+5x+4-4\right)\left(x^2+5x+4+6\right)\)
\(=\left(x^2+5x\right)\left(x^2+5x+10\right)=x\left(x+5\right)\left(x^2+5x+10\right)\)
Chúc bạn học tốt!!!
(x+1)(x+2)(x+3)(x+4)+24
=x(1+2+3+4+24)
x.34
\(\left(x+1\right)\left(x+2\right)\left(x+3\right)\left(x+4\right)+24\)
\(=x\left(1+2+3+4\right)+24\)
\(=10x+24\)