3x/8×4/9x
8mn/15×25r/32m
7a/8b×8b/7a
24xy/17z×34z/15y

Памоги с этим Докажите что 1/51+1/52+1/53+К+1/99+1/100>1/2

3x/8×4/9x=3x×4/8×9x=1/68mn/15×25r/32m=8mn×25r/15×32m=n×5r/3×4=5nr/127a/8b×8b/7a=7a×8b/8b×7a=1/1=124xy/17z×34z/15y=24xy×34z/17z×15y=8x×2/5=16x/5