Question

a.\(\dfrac{2}{\left(x+1\right)\left(x-3\right)}\)

b.\(\dfrac{2x+1}{x^2-5x+6}\)

c.\(\dfrac{1}{x^2+y^2}\)

d.\(\dfrac{5x+y}{x^2+6x+10}\)

Mng giúp em với ạ.Em cảm ơn

 

Answer 1

\(a,\dfrac{2}{\left(x+1\right)\left(x-3\right)}\\ đk\left\{{}\begin{matrix}x+1\ne0\\x-3\ne\end{matrix}\right.=>\left\{{}\begin{matrix}x\ne-1\\x\ne3\end{matrix}\right.\)

\(d,\dfrac{2x+1}{x^2-5x+6}=\dfrac{2x+1}{\left(x-2\right)\left(x-3\right)}\\ đk\left\{{}\begin{matrix}x-2\ne0\\x-3\ne0\end{matrix}\right.=>x\ne2;x\ne3\)

\(c,x^2\ge0\forall x\\ y^2\ge0\forall y\)

=> \(x\ne0;y\ne0\)

\(d,\dfrac{5x+y}{x^2+6x+10}\\ đkx^2+6x+10\ne0\)

 

Answer 2

đề bài là gì em nhỉ