Факториал
15!/14!
8!/10!
42!/40!
16!/14!3!

$frac{15!}{14!} = frac{1*2*3*4*5*6*7*8*9*10*11*12*13*14*15}{1*2*3*4*5*6*7*8*9*10*11*12*13*14} =15$
$frac{8!}{10!} = frac{1}{9*10} = frac{1}{90}$
$frac{42!}{40!} = frac{41*42}{1} =1722$
$frac{16!}{14!3!} = frac{1*2*3*4*5*6*7*8*9*10*11*12*13*14*15*16}{1*2*3*4*5*6*7*8*9*10*11*12*13*14*1*2*3} = frac{15*16}{2*3} = frac{5*8}{1} =40$