Question

Dau coroana !!!
a la a doua - b la a doua =39
a-b=3
Calculati a+b=?

Answer 1

a²-b²=39⇒(a-b)(a+b)=39
3x(a+b)=39
⇒(a+b)=39:3
⇒a+b=13

Answer 2

$a^{2}- b^{2} =(a+b)(a-b)$=39
a-b=3

a+b=13