Question

numarul nat. x care verifica egalitatea [13x x- 416:4]:7=13 reprezinta suma varstelor a lui Vlad si Radu.
stind ca Vlad e mai mare decat Radu cu 3 ani, afle varsta fiecaruia.

Answer 1

[13x-416:4] :7=13          V+R=15 ANI 
13x-104=7*13                V=3+R
13x-104=91                   3+R+R=15
13x=104+91                  2R=15-3
13x=195                       2R=12
x=195:13                      R=12:2
x=15                            R=6
                                   V=6+3
                                   V=12