Question

решите систему уравнений

x+y/2+x-y/3=6
{
x+y/4-x-y/3=6

Answer 1

(x+y)/2+(x-y)/3=6 |*6
(x+y)/4-(x-у)/3=6 |*12

3(x+y)+2(x-y)=36
3(x+y)-4(x-у)=72
3х+3у+2х-2у=36
3х+3у-4х+4у=72
5х+у=36
-х+7у=72

у=36-5х
-х+7(36-5х)=72
-х+252-35х=72
-36х=72-252
-36х=-180
х=-180:(-36)
х=5
у=36-5х
у=36-5*5=36-25=11

Ответ: х=5; у=11