Bạn gõ lại biểu thức đi

Pt đã cho \(\Leftrightarrow3x+10x+8+2x+20x+48=9x+6x-36\Leftrightarrow35x+56=15x-36\Leftrightarrow20x=-92\)

\(\Rightarrow x=\frac{-23}{5}\)

Tao Dùng cách phép chia

:V Đợi tí làm lại đã 

Đang làm tự nhin mất cmnr bài làm

Bài 2

\(a,x^3+2x^2+x\)

\(=x.\left(x^2+2x+1\right)\)

\(b,xy+y^2-x-y\)

\(=y.\left(x+y\right)-\left(x+y\right)\)

\(=\left(y-1\right).\left(x+y\right)\)

bài 3

\(a,3x.\left(x^2-4\right)=0\)

\(\Rightarrow\orbr{\begin{cases}3x=0\\x^2=4\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x=2,x=-2\end{cases}}\)

vậy x=0,x=2 hay x=-2

\(b,xy+y^2-x-y=0\)

\(y.\left(x+y\right)-\left(x+y\right)=0\)

\(\left(y-1\right).\left(x+y\right)=0\)

\(\Rightarrow\orbr{\begin{cases}y-1=0\\x+y=0\end{cases}\Rightarrow\orbr{\begin{cases}y=1\\x=-1\end{cases}}}\)

vậy x=-1, y=1

\(a,\left(x-2\right).\left(x-3\right)-\left(x+3\right).\left(x-3\right)\)

\(=\left(x-3\right).\left(x-2-x+3\right)=x-3\)

\(b,\frac{\left(x^2+4x+4\right)}{x+2}-4x+5=\frac{\left(x+2\right)^2}{x+2}-4x+5\)

\(x+2-4x+5=-3x+7\)

a) \(\left(x-2\right)\left(x-3\right)-\left(x+3\right)\left(x-3\right)\)

\(=\left(x^2-5x+6\right)-\left(x^2-9\right)\)

\(=x^2-5x+6-x^2+9\)

\(=15-5x\)

b) \(\left(x^2+4x+4\right):\left(x+2\right)-\left(4x-5\right)\)

\(=\left(x+2\right)^2:\left(x+2\right)-\left(4x-5\right)\)

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

\(=x+2-4x+5\)

\(=7-3x\)