Question

Solve each system of equations by substitution
-3v-3x=15
5v+x=-29

Answer 1

Divide the first by 3 and something magic may pop out.

Answer 2

I tried to teach you this yesterday and you refused to learn?

Answer 3

I did not refuse I just didn't get it

Answer 4

Well, @overtonka, I think @skullpatrol would be delighted to see you make a better effort, today.

Divide the first equation by 3 and show what you get.

Answer 5

-1v-1x=5

Answer 6

Super! Any suggestion what we should do next?

Hint: I didn't have you divide by 3 just for fun.

Answer 7

solve for one of the variables?

Answer 8

Yes!

Answer 9

so 1v=5-1x?

Answer 10

Now what (hint: use the name of the method)

Answer 11

Since we are using substitition, that would be the things to do.

Please abandon those silly-looking '1's. We don't usually write those unless we are trying to make a point.

Answer 12

ok
so v-x=5?

Answer 13

No, why did you UNsolve? Please "solve for one of the variables".

Answer 14

v=5-x?

Answer 15

Correct.

Answer 16

so plug that in to the other equation?

Answer 17

Substitution principle:

An expression maybe replaced by another expression that has the same value

If $$a=b$$then b maybe substituted for a in any expression.

Answer 18

It's your big chance. Let's see the substitution!