Wiedząc, że media: Wiedząc, że log18 = a i log3 = b, oblicz log40

m: log 2*9 = log 2 + log 9 = a log 2 +log 3² = a log 2 + 2log 3 = a log 2 +2 b = a log 2 = a − 2b log 40 = log (2*2*10) = log 2 +log 2 + log 10 = (a− 2b) +(a − 2b) + 1 = 2a −4b +1