Question

If you wanted to eliminate the y variable by adding the two equations in the following system, what could be your first step?
x − y = 6
4x − 6y = 1

Add the two equations together.

Multiply the first equation by 6.

Multiply the first equation by −6.

Multiply the first equation by −4.

Answer 1

If you wanted to eliminate the y variable
by adding the two equations <- read this part again.........
in the following system, what could be your first step?

Answer 2

I'm not 100% sure but i thought it was a

Answer 3

Multiply the first equation by −6.
(choice c)

Answer 4

from the notes i took The goal of the Elimination Method is to create two equations so that when you add them together, one of the variables cancels out (or sums to zero).

Answer 5

Oh it's c

Answer 6

Do you see why it is 'c'?

Answer 7

Not really

Answer 8

i want to hear this, because I do it differently than the answers above describe. My method works, but I always like learning new techniques

Answer 9

I could see multiplying by 6 so the y's cancel out, but -6?

Answer 10

What would be your choice ehuman do to the different method you do
?

Answer 11

You want to eliminate the 'y' component.
y=-1 in first equation
y=-6 in second equation
we need to get y so that y plus y =0 so we must multiply the first y by -6 changing it into 6y.
add the 2 equations and the y disappears.

Answer 12

ah yes

Answer 13

So what are you trying to say the answer is because i see -6 and 6y

Answer 14

Multiplying by +6 turns the y factor into -6y
making the first equation
6x -6y = 36

Answer 15

+6y -6y = 0

Answer 16

So it's c because multiplying positive 6 will turn the y factor into negative 6 right?

Answer 17

Correct ehuman. and how did you get the -y changed into +6y?

Answer 18

right hellogoodmorning

Answer 19

neat trick, i normally solve for y in terms of x and substitute in the second equation. I'm going to remember this.

Answer 20

Okay! Thanks guys.

Answer 21

u r welcome