450*x-40=500:10
450*x-40=50
450*x=50+40
450*x=90
x=90:450ъ
x=0.2
(450*0.2-40)*10=500
500=500
1 5/15=1 1/3 ;5 15/18=5 5/6; 10 25/75=10 1/3; 4 14/21=4 2/3; 12 4/6=12 2/3 <span>7 26/39=</span><span>7 2/3</span>
31+15=46 ; 78-32=46 - равенство.
64+26=90 ; 24+36=60 - неравенство.
1) 15/16-5/8=15/16-10/16=5/16
2) 3/16+5/16=8/16=1/2
Ответ:1/2
(2х-2у)/у * 3у^2/(х^2-у^2)=
2(x-y)/y**3y^2/(x-y)(x+y)=6y/(x+y)