Question

Daca x la puterea a doua+y la puterea a doua=58 si x-y=4,calculati x+y.URGENT!!

Answer 1

x² +y² = 58
x-y = 4 | ( )²  ⇄ x^2-2xy+y² = 16 ⇆ 58 -2xy = 16  deci  58-16 = 2xy  ⇒ 2xy = 42 ;
(x+y)^2=x²+2xy+y² = 58 + 42 = 100
   ↓
 x+y = √100 = |10 |