Question

Solve the following system using the substitution method:
2x + 4y = 5
x = -2y + 6

Answer 1

You have what x is already, just plug that in: \(\Large 2(-2y+6)+4y=5\)
Now just solve it.

Answer 2

is there a solution coordinate? or is it dependent or inconsistant?

Answer 3

need help?

Answer 4

@alyygirl

Answer 5

yes

Answer 6

you still need help?

Answer 7

yes

Answer 8

ok,what does x equal to?

Answer 9

its no soluion

Answer 10

but is it inconsistent then or dependent

Answer 11

inconsistent

Answer 12

thanks

Answer 13

re ll no solutions inconsistnet

Answer 14

well, in many systems we need to know what does x (or y) equal to and just substitute it in another equation.here we have 2 equation:
x = -2Y +6
2x + 4y = 5
but you know what is x as the question has given:
x = -2y + 6
so we can substiute -2y + 6 in x in this equation: 2x + 4y = 5
so it would be:
2(-2y + 6) + 4y = 5

can u do the rest ;)

Answer 15

are all

Answer 16

ok got that one @PFEH.1999

Answer 17

what about???

Solve the following system using the substitution method:
y = 4x - 5
12x - 3y = 15

Answer 18

and here in this one you have y , it equals to 4x - 5 so substitute y in this equation : 12x - 3y = 15

Answer 19

this one is just like previous one but here you have y , in that one you had x, you should do the same thing ;)

Answer 20

12x+-3(4x-5)=15
12x-12x+15=15

Answer 21

+- what does that mean? :"D

Answer 22

I put that because you need to distribute the negative

Answer 23

so @Venny what are the coordinates or is it no solution

Answer 24

well what did you find when you simplified that alyygirl?

Answer 25

I got always true so its dependent

Answer 26

its equal

Answer 27

Yes itss dependent because its always true

Answer 28

ok

Answer 29

how about this??
Solve the following system using the substitution method:
y = 3x - 9
y = -x - 1

Answer 30

again you can solve it by others way but if you want sybstitution you should find x from this equation:
y = -x - 1

Answer 31

here x = -y - 1

Answer 32

you can substitute -y - 1 instead of x here:
y = -x -9

Answer 33

@PFEH.1999 You can also plug the -x-1 into the first equation

Answer 34

yes we can do this too ;)

Answer 35

Im saying no solution inconsistent?

Answer 36

Thats not what I got
-x-1=3x-9
add x to both sides
-1=4x-9
add 9 to both sides
8=4x
x=2
now we have to find y from x, so we plug x back into one of the original equations
y=3(2)-9
y=6-9
y=-3
so the ordered pair is (2,-3)

Answer 37

so its neither dependent or inconsistent

Answer 38

Yeah, can you answer that ?

Answer 39

thanks got it!

Answer 40

no problem