Odpowiedź:
1.
a)
7a - 1/2a = 7 * 8 - 1/2 * 8 = 56 - 4 = 52
dla a = 8
b)
3b² + 2b = 3(-4)² - 2*4 = 3 * 16 - 8 = 48 - 8 = 40
b = -4
c)
(2x + 3y)(5 - x) = (2*2 - 3*3)(5 - 2) = (4 - 9) * 3 = -5 * 3 = -15
x = 2
y = -3
2.
-x + 1 ≠ x - 1 P
2y + 4 (y + 2) * 2y = 2y² +4y F
3.
4a - 2(3 + a) = -4 - 2(3 - 1) = -4 - 6 + 2 = -10 + 2 = -8 P
5x + 3y - 1 = 5*2 - 3*3 - 1 = 10 - 9 - 1 = 0 F
x = 2
y = -3
a = -1
Szczegółowe wyjaśnienie:
