how to solve each system by elimination -6x-6y=6 and -6x+3y=-12

Question

i dont know how to do this

please explain

Thanks

Answer 1

 -6X - 6Y = 6

 -6X  +3Y = -12

 

  Simplify both equations:

 

        X + Y = -1

       2X - Y = 4

        3X = 3

            X =1

 

          Y =-2

 

      

  

Answer 2

Hi Angelica;

-6x-6y=6

-6x+3y=-12

Let's subtract the second equation from the first...

-6x-(6x)=6x+6x=0

-6y-3y=-9y

6--12=6+12=18

0-9y=18

The x is eliminated...

-9y=18

Let's divide both sides by -9...

(-9y)/-9=18/-9

y=-2

Let's plug this into either equation to establish the value of x.

I randomly select the first equation...

-6x-6y=6

-6x-[(6)(-2)]=6

-6x-(-12)=6

Subtracting a negative number is identical to adding a positive number...

-6x+12=6

Let's subtract 12 from both sides...

-6x+12-12=6-12

-6x=-6

Let's divide both numbers by -6...

(-6x)/-6=-6/-6

x=1

Let plug both values into the second equation to verify...

-6x+3y=-12

[(-6)(1)]+[(3)(-2)]=-12

-6+-6=-12

-12=-12