LIGA ZADANIOWA UMK W TORUNIU 2006/2007
ZADANIA PRZYGOTOWAWCZE DO ETAPU III
DLA KLAS I GIMNAZJUM
Zadanie 24f
Ze wzoruR = (r1 × r2) : (r1 + r2)
wyznacz kolejne zmienne:r1 = ?
R = (r1 × r2) : (r1 + r2) / × (r1 + r2)
R × (r1 + r2) = r1 × r2
r1 × r2 = R × (r1 + r2)
r1 × r2 = R × r1 + R × r2 / - R × r1
r1 × r2 - R × r1 = R × r2
r1 × (r2 - R) = R × r2 / : (r2 - R)
r1 = R × r2 : (r2 - R)
r2 = ?
R = (r1 × r2) : (r1 + r2) / × (r1 + r2)
R × (r1 + r2) = r1 × r2
r1 × r2 = R × (r1 + r2)
r1 × r2 = R × r1 + R × r2 / - R × r2
r1 × r2 - R × r2 = R × r1
r2 × (r1 - R) = R × r1 / : (r1 - R)
r2 = R × r1 : (r1 - R)
Aleksander Wojnowski