Question

{x+3y=0
{y-x=4

{x-5y= -2
{2x+y= -4

{2x-y= -4
{x-2y= 7

{8x-5y= -22
{3x-7y= 2

Answer 1

{x+3y=0
{y-x=4
{3y+x = 0
+
{ y-x= 4
{ 4y= 4 |:4
{y = 1
x+ 3y = 0
x +3 = 0
x = 0-3
x= 3

Answer 2

A){x+3y=0
{y-x=4
x+3y=0
-x+y=4
4y=4
*y=1
1-x=4
-x=4-1
*x=-3

b){x-5y= -2 /*(-2)
{2x+y= -4

-2x+10y=4
2x+y=-4
11y=0
y=0
x-5*0=-2
x=-2


c){2x-y= -4 /*(-2)
{x-2y= 7

-4x+2y=8
x-2y=7
-3x= 15
x=-5
10-y=-4
-y=-4-10
y=14


d){8x-5y= -22 /* (-7)
{3x-7y= 2 /*5

-56x+35y= 154
15x -35y=10
-41x=164
x=-4

8*(-4) -5y =22
-5y=22-32
-5y= -10
y= -2

Answer 3

{x+3y=0
{x-y=4
{x=-3y
{-3y-y=4
{x=-3y
{-4y=4 /(-4)
{x=-3y
{y=-1
{x=-3*(-1)
{y=-1
{x=3
{y=-1




{x-5y=-2
{2x-y=-4
{x=-2+5y
{2*(-2+5y)-y=-2
{x=-2+5y
{-4+10y-y=-2
{x=-2+5y
{9y=2 /9
{x=-2+5y
{y=0,2
{x=-1




{2x-y=-4
{x-2y=7 *(-2)
{2x-y=-4
{-2x+4y=-14
3y=-18 /3
y=-6
{y=-6
{2x-(-6)=-4
{y=-6
{2x=-10 /2
{y=-6
{x=-5



{8x-5y=-22 *7
{3x-7y=2 *(-5)
{56x-35y=-154
{-15x+35y=-10
41x=-164 /41
x=-4
{x=-4
{8*(-4)-5y=-22
{x=-4
{-5y=10 /(-5)
{x=-4
{y=-2