\(x+6734=3478+5782\)

\(x+6734=9260\)

\(x=9260-6734\)

\(x=2526\)

Với \(x\ge0;x\ne4\)

\(=\dfrac{\sqrt{x}\left(\sqrt{x}+2\right)+\left(\sqrt{x}-1\right)\left(\sqrt{x}-2\right)-3\sqrt{x}+2}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}.\dfrac{x-4}{\sqrt{x}-2}\)

\(=\dfrac{x+2\sqrt{x}+x-2\sqrt{x}-\sqrt{x}-2-3\sqrt{x}+2}{x-4}.\dfrac{x-4}{\sqrt{x}-2}\)

\(=\dfrac{2x-4\sqrt{x}}{x-4}.\dfrac{x-4}{\sqrt{x}-2}\)

\(=\dfrac{2\sqrt{x}\left(\sqrt{x}-2\right)}{\sqrt{x}-2}=2\sqrt{x}\)

(1) Phản ứng oxi hoá khử

(2) Phản ứng thế

(3) Phản ứng hoá hợp

Thiếu đk

(1) \(Fe_2O_3+3H_2\xrightarrow[]{t^\circ}2Fe+3H_2O\uparrow\)

(2) \(Fe+2HCl\xrightarrow[]{}FeCl_2+H_2\uparrow\)

(3) \(4Al+3O_2\xrightarrow[]{t^\circ}2Al_2O_3\)

Rút gọn \(-\dfrac{15}{12}=-\dfrac{5}{4}\)

\(\left(\dfrac{1}{12}+x\right)-\dfrac{-1}{2}=\dfrac{-2}{3}\)

\(\dfrac{1}{12}+x=\dfrac{-2}{3}+\dfrac{-1}{2}=\dfrac{-4}{6}+\dfrac{-3}{6}\)

\(\dfrac{1}{12}+x=\dfrac{7}{6}\)

\(x=-\dfrac{7}{6}-\dfrac{1}{12}=-\dfrac{14}{6}-\dfrac{1}{12}\)

\(x=-\dfrac{15}{12}\)

Thiếu ở giữa kìa :>