(х–у)/2–(х+у)/4=–3 |•4
у/2–(х+у)/5=0 |•10
2(х–у)–(х+у)=–12
5у–2(х+у)=0
2х–2у–х–у=–12
5у–2х–2у=0
х–3у=–12
3х–2у=0
х=3у–12
3(3у–12)–2у=0
9у–36–2у=0
7у=36
у=36/7=5 1/7
х=(3•36)/7–12=108/7–12=(108–84)/7=
=24/7=3 3/7
Ответ: (24/7; 36/7)
(х+2у)/10–(х+4у)/3=–8 |•30
(2х–3у)/2–(х+у)/6=0 |•6
3(х+2у)–10(х+4у)=–240
3(2х–3у)–(х+у)=0
3х+6у–10х–40у=–240
6х–9у–х–у=0
–7х–34у=–240
5х–10у=0 |:5
–7х–34у=–240
х–2у=0
х=2у
–7•2у–34у=–240
–14у–34у=–240
–48у=–240
у=5
х=2•5=10
Ответ: (10;5)