Question

What is the value of the y variable in the solution to the following system of equations?
3x - 6y = 12 -2x + 3y = 6

Answer 1

do you know matrices?

Answer 2

not to well my teacher put me in a class i have no idea about

Answer 3

but have you ever experienced matrices? like heard of it?

Answer 4

i heard of it never experienced it but someone on here tried to help but didnt work to good

Answer 5

there is another method, which is just subsitution, its more basic but will still yield the same solution

Answer 6

which would you prefer?

Answer 7

the easiest one

Answer 8

haha. alright lets not do matrices then.

k

lets re-arrange one equation, preferably the first equation as either x or y as the subject. can you do this?

Answer 9

some what you might want to help

Answer 10

Lets re-arrange the first as x as the subject alright.

So we have
3x-6y=12
3x=6y+12
x=(6y+12)/3

Answer 11

follow?

Answer 12

multiply the second eq with 2 then add byt his u can cancel y and u will get the value of x
substitute the obtained value of x in any one eq u will get the value of y

Answer 13

x=2y+4

Answer 14

yeah i follow

Answer 15

alright. so now we have

x=2y+4 and 3y=2x+6

Answer 16

Simply substitute

x=2y+4 into 3y=2x+6

Answer 17

So we get:

3y=2(2y+4)+6

Answer 18

get me?

Answer 19

yeah

Answer 20

So now we just expand the brackets. We solve simultaneously because we now have an equation with one vairable (y).

So:

3y=4y+8+6
3y-4y=14
-y=14
y=-14

Answer 21

So we know y=-14 and that

x=2y+4

Now we can find x by substituting y=-14 into that equation

x=2(-14)+4
x=-28+4
x=-24

Answer 22

therefore x=-24 y=-14 is your solution.

That is, the two lines intersect at the point (-24,-14)

Answer 23

thank you all for helping me because i get freaking lost when it come to math so i get rlly lost when it come to algebra

Answer 24

Just be logical, follow the rules and PRACTICE!