Question

Tìm x:

4/16 = 100/x² -41

Answer 1

\(\dfrac{4}{16}=\dfrac{100}{x^2}-41\)

\(\Leftrightarrow\dfrac{4}{16}=\dfrac{100}{x^2}-\dfrac{41x^2}{x^2}\)

\(\Leftrightarrow\dfrac{4}{16}=\dfrac{100-41x^2}{x^2}\)

\(\Rightarrow4x^2=16\left(100-41x^2\right)\)

\(\Leftrightarrow4x^2=1600-656x^2\)

\(\Leftrightarrow1600-656x^2-4x^2=0\)

\(\Leftrightarrow-660x^2+1600=0\)

\(\Leftrightarrow-660x^2=-1600\)

\(\Leftrightarrow x^2=\dfrac{80}{33}\)

\(\Leftrightarrow x=\pm\dfrac{4\sqrt{165}}{33}\)