Question

x/9=16/x. Aflati-l pe x!

Answer 1

x/9=16/x
x²=9×16
x=√144
x=12
x=-12

Answer 2

$\dfrac{x}{9} = \dfrac{16}{x} \\ \\ Conditie de existenta: ~ x\neq 0 \\ \\ \dfrac{x}{9} = \dfrac{16}{x}\\ \\ \dfrac{x}{9}\cdot x = 16 \\ \\ \dfrac{x^2}{9} = 16 \\ \\ x^2 = 16 \cdot 9 \\ \\ x^2 = 144 \\ \\ \boxed{x = \pm 12 }$