Odpowiedź:
1.
(a - b)² + 2(a + b)(a - b) = a²- 2ab + b² + 2(a² - b²) =
= a²- 2ab + b² + 2a² - 2b²= 3a²- 2ab - b²
Odp: A
2.
(2 - 3x)²= ax² + bx + c
4 - 12x + 9x² = ax² + bx + c
9x² - 12x + 4 = ax² + bx + c
a = 9
b = - 12
c = 4
3.
(3a - 2b)² + (a - 2b)(a + 2b) - 3a(2a - b) =
= 9a² - 12ab + 4b² + a² - 4b² - 6a² + 3ab = 4a² - 9ab
4.
(3x - 4y)² - (x + 2y)² = 9x² - 24xy + 16y² - (x² + 4y + 4y²) =
= 9x² - 24xy + 16y² - x² - 4y - 4y² = 8x² - 24xy - 4y + 12y²
