Răspuns:
3
Explicație pas cu pas:
log2[tex]log_{2} (12*14)-log_{2}21\\\\log_{2}\frac{12*14}{21} /3 (simplifici prin 3)\\\\log_{2}\frac{4*14}{7}\\\\log_{2}4*2\\\\log_{2}8\\\\log_{2}2^{3} = 3\\\ (log_{a}a^{x} = x)[/tex]
