Question

solve y=2x-5, y=6x+6 using systems of equations. Leave all answers in fractional form.

Answer 1

if y equals both 2x-5 AND 6x+6, what does that tell us?

Answer 2

um.. i dont know....

Answer 3

think victoria.
3 equals both 6/2 and 18/6
what does this tell us about the relationship between 6/2 and 18/6?

Answer 4

That they are common factors? Im doing summer homework and i dont remember any of this...

Answer 5

no, don't think of anything you learned at school about math. if 3 = 6/2 and 3 = 18/6,
this tells us that 6/2 = 18/6 since they are both equal to 3.
understand?

Answer 6

Yes. But how does that help me with this problem?
If i wanted to subsitute it, i would need to move one y so its in the equation, right? then but one of the equations in the other equation?

Answer 7

it helps you because y equals both 2x-5 and 6x+6
so that must mean that
2x-5 = 6x+6
solve for x and then substitute in one of the original equations to get y

Answer 8

how do i sovle for x if there is one on either side of the equation?

Answer 9

okay, let me give you an example.
3x-2 = 4x+4
subtract 3x on both sides
3x-3x-2 = 4x-3x+4
which gives
-2 = x +4
subtract 4 on both sides
-2 -4 = x+4-4
which gives
-6 = x
that is,
x = -6

do your problem in a similar fashion.

Answer 10

okay. so i should take 2x-5 = 6x+6 and take 2x off bith sides.
So it would be -5=4x+6, then subtract... 6. right?

Answer 11

that is correct.
very good!

Answer 12

So then it would be -11=4x. so then do i divide -11 by 4?

Answer 13

yes.

Answer 14

but.. i get a decimal? then i put that in one of origonal problems, or both of them?

Answer 15

read what your question says. leave all answers in fractional form. so leave x = -11/4
and substitute thaT fraction in the equation for y

Answer 16

um.. im horrible with fractions. would it be y=2(-11/4)-5... so it would be..
y=-22/8 -5?

Answer 17

\[2 \times \frac{11}{4} = \frac{11}{2}\]

Answer 18

22/8 is the same as 11/4

Answer 19

but then how do i subtract the 5?

Answer 20

http://www.youtube.com/watch?v=52ZlXsFJULI

http://www.youtube.com/watch?v=Mnu16kCRW4U

http://www.youtube.com/watch?v=zQMU-lsMb3U&feature=relmfu

Answer 21

y = (-11/2)-5 = -(11/2)-(10/2) because 5 is the same as 10/2
y = -21/2

I suggest you see all those videos I posted if you want to learn this stuff. they will help you learn fractions properly.

Answer 22

Thanks. Alot. (:

Answer 23

no problem