Question

Daca a^2-b^2=18 iar a-b=9 aflati a+b ma ajutati va tog

Answer 1

$\displaystyle a^2-b^2=18 \\ \\ a-b=9 \\ \\ (a+b)(a-b)=18 \\ \\ 9(a+b)=18 \\ \\ a+b=2$

Answer 2

a^2-b^2=18

 a-b=9

a^2 - b^2 = (a -b) ( a +b)   

9 ( a +b ) = 18

a + b = 18 : 9

a + b = 2