461, 641.

Chúc bạn học tốt nhé! Nhớ k cho mik nha

Gia hưng à~~~

cho tớ hỏi nhé ~ ai cũng đúng mà sao nhấn sai à bạn ^v^?

thứ bảy

855+58

32+1123+ \(x = {-b \pm \sqrt{b^2-4ac} \over 2a}gfdrrffhjxxojmu09\)

là số 4295, 14850,10656

HT

14850

a) \(\left(2x+1\right)x^2=\left(2x+1\right)\left(6x-9\right)\)

\(\Leftrightarrow\left(2x+1\right)x^2-\left(2x+1\right)\left(6x-9\right)=0\)

\(\Leftrightarrow\left(2x+1\right)\left(x^2-6x+9\right)=0\Leftrightarrow\left(2x+1\right)\left(x-3\right)^2=0\)

\(\Leftrightarrow\orbr{\begin{cases}2x+1=0\\\left(x-3\right)^2=0\end{cases}\Leftrightarrow\orbr{\begin{cases}2x=-1\\x-3=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=-\frac{1}{2}\\x=3\end{cases}}}\)

Vậy .......

b) \(\frac{x}{2\left(x-5\right)}+\frac{x}{2x+6}=\frac{4x}{\left(x+3\right)\left(x-5\right)}\) \(\left(ĐKXĐ:x\ne-3;x\ne5\right)\)

\(\Leftrightarrow\frac{x\left(x+3\right)}{2\left(x-5\right)\left(x+3\right)}+\frac{x\left(x-5\right)}{2\left(x-5\right)\left(x+3\right)}=\frac{2.4x}{2\left(x+3\right)\left(x-5\right)}\)

\(\Leftrightarrow\frac{x\left(x+3\right)+x\left(x-5\right)}{2\left(x-5\right)\left(x+3\right)}=\frac{8x}{2\left(x-5\right)\left(x+3\right)}\Rightarrow x\left(x+3\right)+x\left(x-5\right)=8x\)

\(\Leftrightarrow x^2+3x+x^2-5x=8x\Leftrightarrow2x^2-10x=0\Leftrightarrow2x\left(x-5\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}2x=0\\x-5=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\left(TMĐK\right)\\x=5\left(KTMĐK\right)\end{cases}\Leftrightarrow x=0}\)

Vậy.......

ta có : 

\(\frac{7z-1}{6}+2z=\frac{16-z}{5}\)

\(\Leftrightarrow5\times\left(7z-1\right)+60z=6\times\left(16-z\right)\)

\(\Leftrightarrow101z=101\Leftrightarrow z=1\)