Confused on a math question! Please help???

d + e = 12
-d + e = -8

Add the two equations
2e = 4

Now you can solve for e
e = 2

Plug back into either equation to find d
d + 2 = 12
d = 10

So the solution is (10,2)

d + e = 12 → e = 12 - d

- d + e = - 8 → e = - 8 + d


e = e

- 8 + d = 12 - d

d + d = 12 + 8

2d = 20

→ d = 10


Recall: e = 12 - d

e = 12 - 10

→ e = 2

the solution is (10,2).

You have to solve the equations by manipulating them to get rid of one of the variable. Then you solve what's left for the other variable. Then you plug that into one of the starting equations to get the variable you eliminated.

Your equations are perfect for just adding together.
The d's cancel out, and you get:
2e = 4
Now solve that for e, and substitute the answer back in and solve for d.

When you are done, say you got d=10 and e =99 (obviously made up, not the actual answers), you write it as an ordered pair, (10, 99).

Hope that helps.

If 12-d+e=d+e=-8
12+2e=-16
2e=-28
e=-14
12-14-d=d-14=-8
D-14+8=0-->d=14-8=6
-d+(12-14=-2)=-8, d=6

The (,)'s how ever might suggest e is a function of d or something, but that seems impossible if they give the formula like they did.

So either there is one function too many or this is only to determine e when d =6

So if you then treat e as a f(6)=-14) you might still get some where.