a) 4a²- 4a + b²+ 8b+ 17= 0
4a²- 4a + b² + 8b + 16 + 1 = 0
(4a² - 4a + 1) + (b² + 8b + 16) = 0
(2a - 1)² + (b + 4)² = 0
2a - 1 = 0 => 2a = 1 => a = 1/2
b + 4 = 0 => b = - 4
la b) il scrii pe 13 ca 9 + 4
a²+ b²- 6a + 4b + 9 + 4 = 0
a² - 6a + 9 + b² + 4b + 4 = 0
(a - 3)² + (b + 2)² = 0
a - 3 = 0 => a = 3
b + 2 = 0 => b = - 2
