Odpowiedzi

2009-09-10T19:23:52+02:00
A- l. uczniów w klasie Ia

1800=1800/(a-4) +15(a-4) | x (a-4)
1800(a-4)=1800 + 15(a-4)(a-4)
1800a - 15( a^2 - 8a + 16)=9000
1800a - 15a^2 +120a - 240 = 9000
1920a - 15a^2 =9240
15 (128a - a^2) = 9240
128a - a^2 = 616
a=24
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