Question

Найдите x из пропорции 2/5:x=12/25:3/10

Answer 1

$frac{2}{5}:x=frac{12}{25}:frac{3}{10} \\x=frac{frac{2}{5}cdot frac{3}{10}}{frac{12}{25}}\\x=frac{2cdot 3cdot 25}{5cdot 10cdot 12}\\x=frac{1}{4}\\x=0,25$

Answer 2

2/5:x=12/25:3/10
2/5*3/10=12/25*x
6/50=12/25*x
12x=3
x=3/12
x=1/4