Question

{ 3(2x+y) - 5(y-x) = 2(3x-2y)+3(x-y)
{ -5(x+2) +3(y-1) = 4(1-2x) - 2(9+2y)

{ 2(x+3)-(2y-3) = 5(x+2) - 4(y-2)
{ 3(3x+y) +4(y-3x) = 5(y+x) + 2(2y-x)

Answer 1

1)

{ 3(2x+y) - 5(y-x) = 2(3x-2y)+3(x-y)
{ -5(x+2) +3(y-1) = 4(1-2x) - 2(9+2y)

 

{6x+2y-5y+5x=6x-4y+3x-3y

{-5x-10+3y-3=4-8x-18-4y

 

{6x+2y-5y+5x-6x+4y-3x+3y=0

{-5x+3y+8y+4y=4-18+10+3

 

{2x+4y=0  /*5

{-5x+15y=1  / *2

 

10x-20y=0

-10x+30y=2

10y=2  /:10

y=0,2

 

2x+4*0,2=0

2x+0,8=0

2x=-0,8  /:2

x=-0,4

 

{x=-0,4

{y=0,2

 

2)

{ 2(x+3)-(2y-3) = 5(x+2) - 4(y-2)
{ 3(3x+y) +4(y-3x) = 5(y+x) + 2(2y-x)

 

{2x+6-2y+3=5x+10-4y+8

{9x+3y+4y-12x=5y+5x+4y-2x

 

{2x-2y-5x+4y=10+8-6-3

{9x+3y+4y-12x-5y-5x-4y+2x=0

 

{-3x+2y=9

{-6x-2y=0

-9x=9  /:(-9)

x=-1

 

-3*(-1)+2y=9

3+2y=9

2y=9-3

2y=6  /:2

y=3

 

{x=-1

{y=3