Question

boa noite
pessoal me ajudem

a)- {x+y=5
{x+3y=11
b)-{y=3x
{x-y= -6

Answer 1

a){x+y=5
...{x+3y=11 .(-1)

{x+y=5
{-x-3y=-11
0-2y=-6
-2y=-6
y=-6/-2
y=3

x+y=5
x+3=5
x=5-3
x=2




b){y=3x
...{x-y= -6

{-3x+y=0
{x - y =-6
2x+0=-6
2x=-6
x=-6/2
x=-3


y=3x
y=3.(-3)
y=-9

Answer 2

a)- {x+y=5(-1)
      {x+3y=11 

- x - y = - 5
  x+3y = 11
      2y = 6 ==> y = 3
============================================
x = 5 - y ==> x = 5-3 ==> x = 2
==============================================
b)-{y=3x 
{x-y= -6

x - 3x = - 6 ==>  -2x = - 6(-1)==> 2x=6 ==>x = 3

y = 3x ==> y = 3.3 ==> y = 9