PLEASE HELP!

Solve the following system.
x − y = 10
x + y = 8

answer choices:

(−9, 1)

(9, −1)

(9, 1)

(−1, 9)

Question

PLEASE HELP!

Solve the following system.
x − y = 10
x + y = 8 

answer choices:

 (−9, 1) 

 (9, −1) 

 (9, 1) 

 (−1, 9)

anonymous · Answer

add those two equations results in eliminating the y-variable... what equation would you get left?

anonymous · Answer

I tried doing it and got (9,-1)... But i don't know if that's right @dpaInc

anonymous · Answer

since you got (9, -1), if you should plug this back into the original equations.. do they hold up?

anonymous · Answer

No, they do not... @dpaInc

anonymous · Answer

your solution (9, -1)..
 x - y = 10 ---> 9 - -1 = 10, this checks out....
x + y = 8 --->  9 + -1 = 8, this checks out also...

anonymous · Answer

Oh, so what i did was right... i just don't know how to plug it in... I have another question similar to this i'm going to post it now. @dpaInc  thanks

anonymous · Answer

yw...:) 
that is how u should check your answer all the time with systems....