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

$\iff \frac{x\left(x+2\right)}{x\left(x-2\right)}-\frac{x-2}{x\left(x-2\right)}=\frac{2}{x\left(x-2\right)}$

$\iff x^2+2x-x+2-2=0$

$\iff x^2+x=0$

$\iff x\left(x+1\right)=0\iff [\begin{array}{c}x=-1\\ x=0\end{array}$

Phân số mà các bạn

x⁴ - ( 4x - 4 )² = ( x² - 4x + 4 )( x² + 4x - 4 ) = ( x - 2 )²( x² + 4x - 4 )

\(3=a^2+ab+b^2=\left(a+b\right)^2-ab\Leftrightarrow ab=\left(a+b\right)^2-3\ge-3\)

Dấu \(=\)khi \(\orbr{\begin{cases}x=\sqrt{3},y=-\sqrt{3}\\x=-\sqrt{3},y=\sqrt{3}\end{cases}}\).

\(3=a^2+ab+b^2=\left(a-b\right)^2+3ab\Leftrightarrow ab=\frac{3-\left(a-b\right)^2}{3}\le1\)

Dấu \(=\)khi \(\orbr{\begin{cases}x=y=1\\x=y=-1\end{cases}}\).

Nhớ k mình với plz.

d,49(y-4)^2-9(y+2)^2   

đề là ptđttnt hả bạn ? 

a, \(\left(2x+1\right)^2-\left(x-1\right)^2=\left(2x+1-x+1\right)\left(2x+1+x-1\right)=3x\left(x+2\right)\)

b, \(9\left(x+5\right)^2-\left(x-7\right)^2=\left(3x+15\right)^2-\left(x-7\right)^2\)

\(=\left(3x+15-x+7\right)\left(3x+15+x-7\right)=\left(2x+22\right)\left(4x+8\right)=8\left(x+11\right)\left(x+2\right)\)

d, \(49\left(y-4\right)^2-9\left(y+2\right)^2=\left(7y-28\right)^2-\left(3y+6\right)^2\)

\(=\left(7y-28-3y-6\right)\left(7y-28+3y+6\right)=\left(4y-34\right)\left(10y-22\right)\)

\(=4\left(2y-17\right)\left(5y-11\right)\)

chữ đẹp nhỉ

giúp ik

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

\(\Leftrightarrow4x^2-4x\left(x-3\right)+\left(x-3\right)^2=\left[\left(2x\right)-\left(x-3\right)\right]^2=\left(x+3\right)^2=0\)

\(x+3=0\Leftrightarrow x=-3\)

bạn k cho mn đi mn làm bài rồi mà