-x - y = 18
2x - y = -1
How do I solve this? If it helps any I'm currently solving systems of equations using the addition method however, when I try this I end up with x - 2y = 17 and I don't know what to do from there.

Question

-x - y = 18
2x - y = -1
How do I solve this? If it helps any I'm currently solving systems of equations using the addition method however, when I try this I end up with x - 2y = 17 and I don't know what to do from there.

skullpatrol · Answer

First multiply one of the equations by -1 so that when you add the equations the y's will add to 0

anonymous · Answer

Alright, now its
x + y = -18
2x - y = -1
then I use the addition method
3x = -19
x = -19/3

skullpatrol · Answer

$$-x - y = 18$$
$$2x - y = -1$$
$$-1(-x - y) =(-1) 18$$
$$x+y=-18$$
$$2x - y = -1$$

anonymous · Answer

was x = -19/3 correct?

skullpatrol · Answer

You will not be able to check that until you solve for y.

skullpatrol · Answer

Substitute x = -19/3 into one of your equations and solve for y.

anonymous · Answer

How do I do 2 * -19/3? the negative is confusing me.

skullpatrol · Answer

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