Question

[tex] \left \{ {{4x-y-24=2(5x-2y)} \atop {3y-2=4-(x-y)}} \right.
\left \{ {{2(3x-y)-5=2x-3y} \atop {5-(x-2y)=4y+16}} \right.
[/tex]

Answer 1

{4x-y-24=10x-4y⇒ {4x-10x-y+4y=24⇒  {-6x+3y=24
{3y-2=4-x+y       ⇒ {x+3y-y=4+2        ⇒ {x+2y=6           ·6

{-6x+3y=24
{6x+12y=36
   /  15y=60
y=60/15
y=4
din x+2y=6
avem x+2·4=6
x=6-8
x=-2

b) {6x-2y-5=2x-3y  ⇒   {6x-2x-2y+3y=5  ⇒ {4x+y=5
     {5-x+2y=4y+16  ⇒   {-x+2y-4y=16-5  ⇒ {-x-2y=11           ·4

{4x+y=5
{-4x-8y=44
   /  -7y=49
-y=49/7
-y=7        ·(-1)
y=-7
din 4x+y=5 rezulta
4x-7=5
4x=5+7
x=12/4
x=3