Question

VA ROGG AJUTATIMAAA!!!CALCULATI x²+y² DACA :
A)x+y=7 si xy=8
B)x-y=3√3 si xy=12
C)x+Y=3√5 si xy=0

VA ROGG!!!!

Answer 1

A)
(x + y)² = x² + 2xy + y²
=> x² + y² = (x + y)² - 2xy = 7² - 2 × 8 = 49 - 16 = 33

B)
(x - y)² = x² - 2xy + y²
=> x² + y² = (x - y)² + 2xy = (3√3)² + 2 × 12 = 27+ 24 = 51

C) 
(x + y)² = x² + 2xy + y²
=> x² + y² = (x + y)² - 2xy = (3√5)² - 2 × 0 = 45 - 0 = 45