Question

10supra 12 = x supra 6 =?

Answer 1

Se face: produsul mezilor ori produsul extremilor . 
10/2 = x/6 => 12x=60 =>x=60 :12 = 5 

Answer 2

$\frac{10}{12} = \frac{x}{6};$
$x=0,8(3)*6=5;$
$\frac{10}{12}= \frac{5}{6} .$