\(a^3-8a^2+16a=a\left(a^2-2.4a+4^2\right)=a\left(a-4\right)^2\)

\(x^3+2x^2-4x-8=x^2\left(x+2\right)-4\left(x+2\right)=\left(x^2-4\right)\left(x+2\right)=\left(x-2\right)\left(x+2\right)^2\)

a) \(x^3+2x^2y+xy^2-4x=x\left(x^2+2xy+y^2-4\right)=x\left[\left(x+y\right)^2-2^2\right]=x\left(x+y+2\right)\left(x+y-2\right)\)

b) \(x^2-5x-y^2-5y=\left(x^2-y^2\right)-5\left(x+y\right)=\left(x-y\right)\left(x+y\right)-5\left(x+y\right)=\left(x-y-5\right)\left(x+y\right)\)

to cung khong biet cau lam nhu the nao ca

8x4+2=32+2

         =34 

k cho tui nha

a, ĐK : \(x\ne-1;-2\)

 \(\frac{2}{x+1}-\frac{3}{x+2}=\frac{1}{2}\Leftrightarrow\frac{2\left(x+2\right)}{\left(x+1\right)\left(x+2\right)}-\frac{3\left(x+1\right)}{\left(x+1\right)\left(x+2\right)}=\frac{\left(x+2\right)\left(x+1\right)}{\left(x+2\right)\left(x+1\right)}\)

Khử mẫu : \(2x+4-3x-3=x^2+x+2x+2\)

\(\Leftrightarrow-x+1=x^2+3x+2\Leftrightarrow-x^2-4x-1=0\)

giải delta nốt nhé ! 

b;c tương tự 

nếu đơn vị chỉ có 50 người thì đủ ăn trong số ngày là:

(100:50)+30=60 (ngày)

ĐS: 60 ngày

\(A=\left(x+3\right)^2+\left(x-2\right)^2-2\left(x+3\right)\left(x-2\right)=\left(x+3-x+2\right)^2=5^2=25\)

\(A=\left(x+3\right)^2+\left(x-2\right)^2-2\left(x+3\right)\left(x-2\right)\)   

\(=\left[\left(x+3\right)-\left(x-2\right)\right]^2\)   

\(=\left(x+3-x+2\right)^2\)   

\(=5^2\)   

\(=25\)

\(pt\Leftrightarrow x^2-4=x^2-2xm+m^2\Leftrightarrow2xm-m^2=4\Leftrightarrow2xm-4=m^2\)

m-4/m=2x

nhầm tí

\(m=x-\sqrt{x^2-4}\)

với x=<-2;x>=2