{x+y=8

{x-y+2

{x+y=8

{x-y+2

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Wilton, CT

The whole trick with this system is add the equations to get x, subtract the equations to get y

x+y=8

x-y=2

add and get

x+y=8

x-y=2

add and get

2x=10, x=5

subtract and get

2y=6, y=3

Middletown, CT

Hi Danielle;

I think that the { is incorrectly placed. I will proceed anyway. If I am mistaken, please let me know.

{x+y=8

x+y=8

{x-y+2

I am also assuming this is x-y=2

x-y=2

The addition method requires only one variable. So let's isolate one variable in each equation. I randomly choose the y.

x+y=8

y=8-x

x-y=2

-y=2-x

y=x-2

Do you understand the last revision? I multiplied both sides by -1 to eliminate the negative sign and completely isolate y.

8-x=x-2

Let's add 2 to both sides...

2+8-x=x-2+2

10-x=x

Let's add x to both sides...

x+10-x=x+x

10=2x

Let's divide both sides by 2...

10/2=2x/2

5=x

Let's solve for y...

x+y=8

5+y=8

y=3

x-y=2

5-y=2

y=3

I hope this helps. Please let me know either way. Did I make correct assumptions?

Mark D.

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New York, NY

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John P.

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