Question

y=2x-3
6y=12x+18
Help me out here guys!

Answer 1

Can i have your assistance once more? @sjerman1

Answer 2

System of equations?

Answer 3

Maybe I can help...

y = 2x-3

so you can substitute that into the second equation.... what do you get?

Answer 4

alright

Answer 5

on the second equation just divide the right side by 6!

Answer 6

y=2x-3
6y=12x+18

---------------
6(2x-3) = 12x + 18

Solve for x.

Then once you have x plug it into either of the equations to get y.

Answer 7

ok, which leaves you with y.

Answer 8

substitution or elimination?

Answer 9

It doesn't really matter the method. In this case, substitution is easiest.

Answer 10

@sephl @ryan123345 haha this one is plotting lines,

Answer 11

yip, exactly what @SephI said

Answer 12

it's not substituiton or elimination?

Answer 13

huh? You didn't clarify what you wanted. Do you want us to graph?

Answer 14

@thisisarri
y=2x-3
6y=12x+18 -> y=2x+3

Answer 15

no worries @SephI @ryan123345 i got this one.
I have been helping her on these for a while now

Answer 16

Alright.

Answer 17

that is a couple lvls above what she is doing right now, but thank you!

Answer 18

ahahah that was confusing.

Answer 19

but with the two equations you have now @thisisarri
y=2x-3
y=2x+3
just go ahead and plot them

Answer 20

That's both equations?

Answer 21

keep in mind that when you have something that is attached to your y
6y=12x+18
doesnt matter what it is the only way to move the 6 over is to divide

Answer 22

yes, @thisisarri , the y=2x+3 came from 6y=12x+18 after moving the 6 over to the right side

Answer 23

ahh, okay. I wrote all this down so i can have it for the next one like this!

Answer 24

You've helped so much, ahh!

Answer 25

just like the one we did earlier, what we did in this one 6y=12x+18 is \[y=\frac{ 12x }{ 6 } +\frac{ 18 }{ 6 }\]
we did this because when moving the 6 from the left side to the right side we must divide, because it was multiplied to the y. does this make sense @thisisarri ?

Answer 26

yes, it makes sense. Jut divide the numbers by 6. not very hard

Answer 27

i have another question.

Answer 28

go for it

Answer 29

okay, so A cell phone company offers a plan that is $30 dollars per month plus $0.10 per text message sent or recieved. A comparable plan costs $60 dollars per month but offers ulimited text messaging. Part A: How many text messages would have to be sent or recieved in order for the plans to cost the same each month? Part B: If you recieved an average of 150 texts per month which plan would you choose? Why?

Answer 30

alright lets start with a
30+.1(x)=60

Answer 31

so just like with the other problems solving for y this time we are solving for x

Answer 32

gotcha. so what do we do now?

Answer 33

we have $30 for the plan plus .1(times the number of text messages [x]) is equal to = $60 for the unlimited plan

Answer 34

right!

Answer 35

so there are two different ways to solve this, some people like to get rid of the decimal in the beginning and others will just leave it like this. what would you like to do?

Answer 36

we can leave it. it's fine

Answer 37

well a better question is, are you aloud to use a calculator now or on the test?

Answer 38

haha yes, i am.

Answer 39

awesome, so 30+.1(x)=60 we are going to move the 30 over to the right side like this