A)
{-2(x+2)+3y=-y-4
{5(x-1)=x-3(x+y)-1
{-2x-4+3y+y+4=0
{5x-5=x-3x-3y-1
1{-2x+4y=o
2{7x+3y=4
2x=4y
x=2y
14y+3y=4
17y=4
y=4/17
x=8/17
b)
{2(x-4y)=4x-y
{4x-4y=-8
{2x-8y-4x+y=0
{x-y=-2
{-2x-7y=0
{x=y-2
-2y+4-7y=0
-9y=-4
y=4/9
x=-14/9
2.
{-x+4y+7=0
{0,3x-0,4y+0,5=0
x=4y+7
0.3*(4y+7) - 0.4y + 0.5 =0
1.2y + 2.1 - 0.4y + 0.5 = 0
0.8y = -2.6
y= -3.25
x= -6