Question

tìm x:6/8=15/x

Answer 1

\(x:\dfrac{6}{8}=\dfrac{15}{x}\)

\(\Leftrightarrow x^2=\dfrac{45}{4}\)

hay \(x\in\left\{\dfrac{3\sqrt{5}}{2};-\dfrac{3\sqrt{5}}{2}\right\}\)

Answer 2

\(x:\dfrac{6}{8}=\dfrac{15}{x}\)

<=> \(x.\dfrac{4}{3}=\dfrac{15}{x}\)

<=> \(\dfrac{4x}{3}=\dfrac{15}{x}\)

<=> 4x . x = 15 . 3

<=> 4x² = 45

<=> x² = \(\dfrac{45}{4}\)

<=> \(x=\dfrac{\sqrt{45}}{2}\)