Question

Помогите
100!/99!-99!/98!
50!/48!-30!/98!

Answer 1

$frac{100!}{99!}-frac{99!}{98!}=frac{99!, cdot , 100}{99!}-frac{98!, cdot 99}{98!}=100-99=1\\\frac{50!}{48!}-frac{30!}{28!}=frac{48!, cdot 49cdot 50}{48!}-frac{28!, cdot , 29cdot 30}{28!}=49cdot 50-29cdot 30=2450-870=1580$