Question

Daca impartim suma dintre 55 si un numar ,,z'' la predecesorul lui ,,z'' obtinem catul 5 si restul 4. Poti afla numarul ,,z"?

Answer 1

$(55+z): (z-1)=5 \ rest \ 4 \\\\ 55+z=5(z-1)+4 \\\\ 55+z=5z-5+4 \\\\ 55+z=5z-1 \\\\ z-5z=-1-55 \\\\ -4z=-56 \ \ \ |:(-4) \\\\ \boxed{z=14}$