\(\dfrac{17}{2}:x=5\)

\(x=\dfrac{17}{2}:5=\dfrac{17}{2}\times\dfrac{1}{5}\)

\(x=\dfrac{17}{10}\)

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\(x-\dfrac{3}{8}=2+\dfrac{1}{4}\) \(=\dfrac{8}{4}+\dfrac{1}{4}\)

\(x-\dfrac{3}{8}=\dfrac{9}{4}\)

\(x=\dfrac{9}{4}+\dfrac{3}{8}=\dfrac{18}{8}+\dfrac{3}{8}\)

\(x=\dfrac{21}{8}\)

Chọn phương án D.

Cấu trúc: Would you like + to V

Em cảm ơn cô, mẹo rất hữu ích ạ. Em thường học1,2 và 4 ạ.

Giải phương trình: (Giải chi tiết giúp mình với).

\(\sqrt{x}+\sqrt{x+3}+2\sqrt{x^2+3x}+2x=9\)

\(\dfrac{1}{3}+\dfrac{1}{6}+\dfrac{4}{3}+\dfrac{2}{6}+\dfrac{2}{3}+\dfrac{5}{6}\)

\(=\left(\dfrac{1}{3}+\dfrac{4}{3}+\dfrac{2}{3}\right)+\left(\dfrac{1}{6}+\dfrac{2}{6}+\dfrac{5}{6}\right)\)

\(=\dfrac{7}{3}+\dfrac{8}{6}\)\(=\dfrac{7}{3}+\dfrac{4}{3}\)

\(=\dfrac{11}{3}\)

\(4\dfrac{1}{2}-\dfrac{3}{4}=\dfrac{9}{2}-\dfrac{3}{4}=\dfrac{36}{8}-\dfrac{6}{8}=\dfrac{30}{8}=\dfrac{15}{4}\)

\(\dfrac{5}{x+2}=\dfrac{6}{x-3}\) (ĐK: \(x\ne-2;x\ne3\))

\(\Rightarrow5\left(x-3\right)=6\left(x+2\right)\)

\(\Leftrightarrow5x-15=6x+12\)

\(\Leftrightarrow-15-12=6x-5x\)

\(\Leftrightarrow-27=x\)

\(\Leftrightarrow x=-27\) (TMĐK)

Vậy \(S=\left\{-27\right\}\).