Question

I think I have the right answer, but I am not sure.
Solve the system by the elimination method.
x + y - 6 = 0
x - y - 8 = 0
When you eliminate y , what is the resulting equation?

Answer 1

2x=14

Answer 2

yes your right

Answer 3

they may want you to write it as
2x-14=0

though it is true
2x=14
and also
x= 7

Answer 4

great, thanks!

Answer 5

notice you add the two equations
and that is what you get
2x + 0 -14= 0
which we would write as
2x-14=0

Answer 6

Can you help with another?

Answer 7

did you post it?

Answer 8

Solve the system by the elimination method.
3x - 2y - 7 = 0
5x + y - 3 = 0
To eliminate y, the LCM is 2. Which of the following is the resulting equations?

Answer 9

1. 3x - 2y - 7 = 0

5x + y - 3 = 0
-
2. 3x - 2y - 7 = 0

-10x - 2y + 6 = 0
-
3. 3x - 2y - 7 = 0

10x + 2y - 6 = 0

Answer 10

My question is, do you multiply each term by 2? Or just "y"?

Answer 11

you multiply both sides of the equation by 2 (both sides to keep it equal)
think of it as: double the left side and double the right side
of course, the right side is 0 and 2*0 is still 0

on the left side, you have to double (i.e. multiply by 2) each term

Answer 12

it's easier to see with numbers:
1+1 = 2
if you multiply both sides by 2 you write:
2*(1+1) = 2*2
2*1 + 2*1 = 4
2+2= 4
4=4
it works

Answer 13

So
2* (3x) (- 2y) (- 7) = 0 (2)
6x-4y-14=0
And
5x + y - 3 = 0
10x+2y-6=0

Answer 14

yes, you could multiply the top eq. by 2
but we don't want to do that. we want the number in front of the y to be the same number. ( or the minus of it). so we only do the bottom equation.

Answer 15

So the answer would be
3.
3x - 2y - 7 = 0

10x + 2y - 6 = 0?

Answer 16

yes. the idea is both equations are still true (multiplying the 2nd eq by 2 does not make it wrong, just different)
now we add them
we would get
13x +0 - 13=0
or just
13x -13=0
and we are are our way to solving for x

Answer 17

Thank you.