Question

Scrieți toate numerele de forma 645ab divizibile cu 45

Answer 1

Răspuns:

sper ca este bine...succes ♥️

Answer 2

$\it n=\overline{645ab},\ \ n=?\\ \\ \\ \overline{645ab}\ \vdots\ 45 \Rightarrow\begin{cases} \it \overline{645ab}\ \vdots\ 5 \Rightarrow b\in\{0,\ 5\}\\ \\ \it \overline{645ab}\ \vdots\ 9 \Rightarrow \ (6+4+5+a+b)\ \vdots\ 9 \Rightarrow \ (15+a+b)\ \vdots\ 9\end{cases}\\ \\ \\ b=0 \Rightarrow (15+a)\ \vdots \ 9 \Rightarrow a=3\Rightarrow n=64530\\ \\ b=5 \Rightarrow (15+a+5)\ \vdots \ 9 \Rightarrow (20+a)\ \vdots\ 9 \Rightarrow a=7\Rightarrow n=64575$