Question

Suma  a doua numere este 7,21,iar diferenta lor este 2,17.Calculati numerele.

 

Answer 1

$a+b=7,21\\ \underline{a-b=2,17} \ \ |(+) \\\\ 2a \ / \ =9,38 \ \ \ |:2\\\\ \\ \boxed{a=4,69} \\\\ b=7,21-4,69 \\\\\\ \boxed{b=2,52}$

Answer 2

a+b=7,21
a-b=2,17
din prima rezula a=7,21-b
si inlocuiesti in a doua 7,21-b-b=2,17
apoi calculezi asa 7,21-2b =2,17
-2b=2,17-7,21 /*(-1)
2b=7,21-2,17
2b=5,04
b=5,04/2
b=2,52