5(х+1,4у)-0,8(2х+у) = 5x+7y-1,6x-0,8y = 3,4x+6,2y
<span>2/3(х-у+z)-(2/3х-у+z) = 2/3x-2/3y+2/3z-2/3x+y-z = 1/3y-1/3z = y/3-z/3</span>
739:8=92 остаток 3 6780:90=75остаток 30 47350:60=789 остаток 10
23070:40=576 остаток 30
1.
2 1/15-3/4x=59/60
31/15-3/4x=59/60
124-45x=59
-45x=59-124
-45x=-65
x=13/9
2.
x-5/7x=2/3
21x-15x=14
6x=14
x=7/3
3.
(3/14+5/21y):3/7=3 1/4
(3/14+5/21y)*7/3=13/4
1/2+5/9y=13/4
18+2)y=117
20y=117-18
20y=99
y=99/20
4.
7/30+x=11/30
x=11/30-7/30
x=2/15
(√в-3√а)(√в+3√а)-в=в-9а-в=9а