3x-4y=-31
x+y=6
how do you solve this equation out i'm so confused

3x-4y=-31
-3(x+y)=6

3x-4y=-31
-3x-3y=-18

-7y=-49

y=7

x+y=6
x+7=6
  -7  -7

x=-1

x=-1
y=7

(-1,7)

 

{ 3 x - 4 y = - 31
     x  + y = 6        * ( - 3 )

 3 x - 4 y = - 31
-3x  - 3 y = - 18

        - 7 y =  - 49   * ( -1)
             
             y = 49 / 7
            
              y = 7

For x :

x  + y = 6 

x + 7 = 6

x = 6 - 7

x = -1

S = { - 1 , 7 }

hope this helps!

I’m going to infer you said parallel.solve for yy= -1/2x+7/4lines that are parallel have the same slope, different y intercept.so we know m is -1/2then from there solve for y intercept.