Question

`Marcela avea 10 ani cand tatal ei avea 35 de ani. Acum au impreuna 55 de ani

Answer 1

Notam cu x - nr de ani ce au trecut.
10+x+35+x=55
45+2x=55
2x=55-45
2x=10
x=10/2
x=5
10+x=10+5=15(ani are Marcela)
35+x=35+5=40(ani are tatal ei)