Question

Answer 1

lớp 6 học cái này rồi hả? Nhìn lạ ghê á=''))

Answer 2

a: \(A=\dfrac{\sqrt{x}\left(2-\sqrt{x}\right)+x+4}{4-x}:\dfrac{2\sqrt{x}+1-\sqrt{x}+2}{\sqrt{x}\left(\sqrt{x}-2\right)}\)

\(=\dfrac{2\sqrt{x}-x+x+4}{4-x}\cdot\dfrac{\sqrt{x}\left(\sqrt{x}-2\right)}{\sqrt{x}+3}\)

\(=\dfrac{2\sqrt{x}\left(\sqrt{x}+2\right)\left(\sqrt{x}-2\right)}{-\left(x-4\right)\cdot\left(\sqrt{x}+3\right)}=\dfrac{-2\sqrt{x}}{\sqrt{x}+3}\)

b: A=-1/3

=>\(\dfrac{2\sqrt{x}}{\sqrt{x}+3}=\dfrac{1}{3}\)

=>\(6\sqrt{x}=\sqrt{x}+3\)

=>5*căn x=3

=>căn x=3/5

=>x=9/25