What would you like to ask?how to solve 3x + y = -8 and -2x - y =6? please please?

2009-01-11 6:36 am
thisis geting more confusing..

回答 (3)

2009-01-11 9:56 am
✔ 最佳答案
3x + y = -8 (solve by using elimination)
-2x - y = 6

...3x + y = -8
+) -2x - y = 6 (addition)
------------------------
x = -2

-2x - y = 6
-2(-2) - y = 6
4 - y = 6
y = 4 - 6
y = -2

∴ x = -2 , y = -2
2009-01-11 4:35 pm
Adding gives :-
x = - 2

- 6 + y = - 8
y = - 2

x = - 2 , y = - 2
2009-01-11 2:45 pm
Add the two equations to get x=-2.
Substitute that back into one of the equations, and solve for y and get y=-2.


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