Question

tìm x

làm câu 11-12

Answer 1

11) \(\sqrt{\dfrac{3}{4}x}-\dfrac{1}{2}=\dfrac{3}{7}\left(x\ge0\right)\)

\(\Rightarrow\sqrt{\dfrac{3}{4}x}=\dfrac{3}{7}+\dfrac{1}{2}\)

\(\Rightarrow\sqrt{\dfrac{3}{4}x}=\dfrac{13}{14}\)

\(\Rightarrow\dfrac{3}{4}x=\left(\dfrac{13}{14}\right)^2\)

\(\Rightarrow\dfrac{3}{4}x=\dfrac{169}{196}\)

\(\Rightarrow x=\dfrac{169}{196}:\dfrac{3}{4}\)

\(\Rightarrow x=\dfrac{169}{147}\)

12) \(\dfrac{2}{3}+\sqrt{\dfrac{1}{3}:x}=\dfrac{3}{5}\left(x>0\right)\)

\(\Rightarrow\sqrt{\dfrac{1}{3}:x}=\dfrac{3}{5}-\dfrac{2}{3}\)

\(\Rightarrow\sqrt{\dfrac{1}{3}:x}=-\dfrac{1}{15}\) 

Do biểu thức trong dấu căn luôn dương nên không có x thỏa mãn