Question

1/2 inmultit cu x= 80 am uitat cum se rezolvau problemele astea

Answer 1

$\displaystyle{ \frac{1}{2} \cdot x = 80 }$

Metoda 1

$\displaystyle{ \frac{x}{2} = 80 }$

$\displaystyle{ x = 2 \cdot 80 }$ (se inmultesc mezii cu extremii, pe diagonala)

$\boxed{x=160}$

Metoda 2

$\displaystyle{ x \cdot \frac{1}{2} = 80 }$

$\displaystyle{ x = 80 : \frac{1}{2} }$

$\displaystyle{ x = 80 \cdot \frac{2}{1} }$

$\boxed{x=160}$