Răspuns :
1)
(x + 2)(x - 3) + 3x + 7 =
= x² + 2x - 3x - 6 + 3x + 7
= x² + 2x + 1
= (x + 1)²
2)
x² - y² = (x - y)(x + y) = 6 si (x + y) = 3 => (x - y) = 2
a = (x - y) + (x - y)² + (x - y)²
= 2 + 4 + 4
= 10
1)
(x + 2)(x - 3) + 3x + 7 =
= x² + 2x - 3x - 6 + 3x + 7
= x² + 2x + 1
= (x + 1)²
2)
x² - y² = (x - y)(x + y) = 6 si (x + y) = 3 => (x - y) = 2
a = (x - y) + (x - y)² + (x - y)²
= 2 + 4 + 4
= 10