a)0-0=0x0=0:0
b)0+0=0x0=0:0
Đúng thì tk nha
\(x-y=xy=\dfrac{x}{y}\)
Ta có:
\(x-y=xy\Leftrightarrow x-y-xy=0\)
\(\Leftrightarrow x-y-xy+1=1\)
\(\Leftrightarrow x\left(1-y\right)+1\left(1-y\right)=1\)
\(\Rightarrow\left(x+1\right)\left(1-y\right)=1\)
Xét ước nhé
\(x+y=xy=\dfrac{x}{y}\)
Ta có:
\(x+y=xy\Leftrightarrow x+y-xy=0\)
\(\Leftrightarrow x+y-xy-1=-1\)
\(\Leftrightarrow x\left(1-y\right)-1\left(1-y\right)=-1\)
\(\Leftrightarrow\left(x-1\right)\left(1-y\right)=-1\)
Xét dấu nha