Respuesta :

osikbro

Answer:

The first equation should be multiplied by -3

Step-by-step explanation:

If you multiply the first equation by -3, then you can cancel out the 9x's in both equations by adding them together, leaving only the y's. Hope this helps!

Answer:

x=-4

y=-4

Step-by-step explanation:

add -12x+12y=0

12y=12x

y=x

substitute in first eq.

-3x+7x=-16

4x=-16

x=-16/4=-4

y=x=-4

Or

multiply first eq. by -3

9x-21y=48

-9x+5y=16

add

-16y=64

y=64/-16=-4

substitute in first eq.

-3x+7(-4)=-16

-3x-28=-16

-3x=-16+28

-3x=12

x=12/-3=-4

so x=-4

y=-4

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