Odpowiedź:
Zad. 1
8 - 2x = 3(5 - x)
8 - 2x = 15 - 3x
-2x + 3x = 15 - 8
x = 7
Odp. B
Zad 2.
x² + 2x - 15 = 0
A. (-5)² + 2 · (-5) - 15 = 0
25 - 10 - 15 = 0
0 = 0
B. (-3)² + 2 · (-3) - 15 = 0
9 - 6 - 15 = 0
-12 = 0
C. 3² + 2 · 3 - 15 = 0
9 + 6 - 15 = 0
0 = 0
D. 5² + 2 · 5 - 15 = 0
25 + 10 - 15 = 0
20 = 0
Poprawne odp. to A i C
