Question

Please help!!!!!!! I will reward you with e medal just please help!!!!!!!!!!!!

Answer 1

Solve using two different methods. Explain which method you found to be more efficient.
a. 3x – 9y = 3 b. 7x – 3y = 20 c. y = 1/2x - 6
6x – 3y = -24 5x + 3y = 16 2x + 6y = 19

Answer 2

I would help you with this but I took this in middle school! and then my freshman year and now im a senior. I forgot. I'm so sorry

Answer 3

Someone will help you though!

Answer 4

=( its ok i just dont know and i want it done but i cant figure it out!
But thanks anyway!

Answer 5

i can help

Answer 6

YAY Please help I need help with b and c...

Answer 7

have you taken the first equation and isolated one variable yet?

Answer 8

Substitution method
3x - 9y = 3
Dividing throughout by 3,we get
x - 3y = 1
x = 1 + 3y ..... ( i )
6x - 3y = - 24 .....( ii )
that's all i know

Answer 9

i have no clue what that means @swmchick

Answer 10

actually ignore that

Answer 11

if you look at the two problems, you notice one has a -3y and the other is +3y right?

Answer 12

ya

Answer 13

so would i add both equations together then

Answer 14

so what you can do is set up one giant addition problem that will look like this \[(7x-3y=20)-5x=3y=16\]

Answer 15

exactly. just add all like variables and its easy to solve for x

Answer 16

ok i got x now what do i do to get y?

Answer 17

then all you have to do is plug that value back into any equation to solve for y

Answer 18

now is that substitution?

Answer 19

yes :)

Answer 20

tell me when you got it and we can move to c

Answer 21

ok so for x i got x=3 and for y i got y = -1 2/3
is that correct?

Answer 22

sounds right

Answer 23

to check just plug it into the other equation :)

Answer 24

ok now for c would we do elimination?

Answer 25

Because I ave no clue how to do that lol.

Answer 26

you would do the same thing you did for b. it just requires one more step.
you would rearrange the first equation to 1/2x - y = 6
Then multiply that whole equation by -4

Answer 27

you would get -2x=4y=-26

Answer 28

then you can make both of the equations into one big addition problem and solve the same way you did for b

Answer 29

you mean -2x + 4y = -24

Answer 30

yes. sorry. typo

Answer 31

are you all good? :)

Answer 32

ok i am solving right now give me just a second.

Answer 33

can you solve my problem after?

Answer 34

i can try yes.

Answer 35

ok so i got x=11 and y= -1/2
is that right and did we use substitution again?

Answer 36

yeah

Answer 37

KEWL! Thanks ok so give me the link to yours and ill see if i can solve it.

Answer 38

http://openstudy.com/study#/updates/50b820ade4b07527f06b935f