2a-b=5
4a-2b = 2(2a - b) = 2*5=10
2(1-х)-4(5-2х) > 3-11(1-х)
2-2х-(20-8х) > 3-(11-11х)
2-2х-20+8х > 3-11+11х
2-20-3+11 > 11х+2х-8х
-10 > 5х |/5
-2 > х
Ответ: х < -2; х∈(-∞;-2).
{<span>2х+5у=8 /х3
</span>{-3х+2у=7 /х2
<span>{6х+15у=24
</span><span>{-6х+4у=14
</span>19у=38
у=2
2х+10=8
2х=-2
х=-1