Question

6.02] For the following system, if you isolated x in the second equation to use the Substitution Method, what expression would you substitute into the first equation?

3x + y = 8
-x - 2y = -10

-2y + 10

2y + 10

2y - 10

-2y - 10

Answer 1

Is it B?

Answer 2

Yes.

Answer 3

Wait, no

Answer 4

It's the first one.

Answer 5

Oh, how? Do you keep the 2 negative?

Answer 6

Solve -x - 2y = -10 for x.

add the 2y to the other side: -x=2y-10

Now multiply by -1, you can't have a negative x

so x=-2y+10

Answer 7

Oh, got it, thx, lol! :D

Answer 8

sure thing.