Question

Số giá trị thỏa mãn là...

Answer 1

ĐKXĐ: \(x\ne0\)

\(\frac{2x}{42}=\frac{28}{3x}\) \(\Leftrightarrow\) \(\frac{x}{21}=\frac{28}{3x}\)

\(\Rightarrow3x^2=588\)

\(\Leftrightarrow x^2=196\)

\(\Leftrightarrow\left[\begin{matrix}x=14\\x=-14\end{matrix}\right.\)(thỏa mãn ĐKXĐ)

Answer 2

2

Answer 3

\(\frac{2x}{42}=\frac{28}{2x}\Rightarrow\frac{x}{21}=\frac{14}{x}\)

\(\Rightarrow x^2=21.14\)

\(\Rightarrow x^2=294\)

\(\Rightarrow x=\left[\begin{matrix}7\sqrt{6}\\-7\sqrt{6}\end{matrix}\right.\)

Answer 4

2x.3x = 42.28

6x² = 6.7.28

x² =7.28

x² = 196

x² = ( \(\pm\) 14 )²

=> x = \(\pm14\)