Question

Daca inmultim un numpar cu 2/3 , iar rezultatul il aduman cu 1/2 obtinem 1 zecime si o doime. Sa se afle numarul

Answer 1

(a×2/3)+1/2=1/10+1/2
2a/3+1/2=1/10+5/10
4a/6+3/6=6/10
10×(4a+3)=36
4a+3=36:10
4a+3=3,6
4a=3,6-3
4a=0,6
a=0,6:4
a=6/10×1/4
a=6/40
a=3/20 sau a=0,15