Odpowiedź:
6s + 5 = 21 - 2s
6s + 2s = 21 - 5
8s = 16 /: 8
s = 2
Spr.: L = 6s + 5 = 6 • 2 + 5 = 12 + 5 = 17
P = 21 - 2s = 21 - 2 • 2 = 21 - 4 = 17
L = P
Pozdrawiam.
