Question

PLEASE HELP? SERIOUSLY? :)

Solve 2x + 5y = -133x - 4y = -8

(4, 1)

(-4, 1)

(4, -1)

(-4, -1)

Answer 1

is that a set of coordinates?

Answer 2

YES

Answer 3

:)

Answer 4

what is it ? : 2x + 5y = -133x - 4y = -8
why there are 2 equal signs

Answer 5

To solve by addition, you need to determine the factors that eliminates one of the variables for each equation. E.g.

4(2x + 5y = -9)
5(3x - 4y = -2)

8x + 20y = -36
15x - 20y = -10

23x = -46
x = -2

Substitution method? Take one of the equations and solve for the variable. Then, substitute that for another equation. Simplify.

Answer 6

I don't know, it's set up in the weirdest way....

Answer 7

wait.. it look like that the two equations are :
2x + 5y = -9
3x - 4y = -2
?

Answer 8

Disregard the long, drawn out example i made

Answer 9

ok.. its hard to understand what are you two equations from
2x + 5y = -133x - 4y = -8

it might be :

2x + 5y = -13 , 3x - 4y = -8

Answer 10

Hmm that would make more sense, is that your system Chao?

Answer 11

yes the OP equation dosent make sense

Answer 12

ok ok ok now this is starting to make sense :)

Answer 13

YES! 2x + 5y = -13 , 3x - 4y = -8

Answer 14

if so .. we might multiply the first by 3
multiply the second by 2

then subtract the second from the first :
3(2x + 5y) = -13 * 3
2(3x - 4y) = -8 * 2

6x + 15y = -39
6x -8y = -16

6x + 15y -(6x-8y) = -39 - (-16)
15y + 8y = -23
23y = -23

y = -1

can you tell what is x now ?

Answer 15

It's either 4, or -4

Answer 16

How do I solve for x....?

Answer 17

now go back to one of the original equations :
for example : 2x + 5y = -13

plug in here y = -1

what you get for x ?

Answer 18

If you have an x=a (a being some number) then plug a into your equation and find y, then you will have (x,y)

Answer 19

What number though?

Answer 20

Oh, okay!!!!! I'll use one of the numbers from the multiple choice?

Answer 21

Hear back from your professor yet, @InsanelyChaotic ?

Answer 22

Sorry, I know I sound like a dumb*** and get overly excited when I know something pertaining to math but bear with me

Answer 23

you have to solve one of the equations for x, then substitue that value into the other.

Answer 24

Yes @CliffSedge

Answer 25

look at what i wrote :

now go back to one of the original equations :
for example : 2x + 5y = -13

plug in here y = -1

what you get for x ?

if you plug y = -1 into 2x + 5y = -13
you get

2x -5 = -13
2x = -8
x= -4

Answer 26

I know this much, thank you

Answer 27

in fact you could, instead of solving it
just plug the choices that you got up there and see
which of them holds for your equations

Answer 28

Okay

Answer 29

I'm so confused

Answer 30

I know this should be simple but it's not

Answer 31

F*** math

Answer 32

:(

Answer 33

what you have here are two equations that share the same value for x and y. so say you solve one equation and get x=(y with math done to it) then plug (y with math) into the other equation for x and get a value for y

Answer 34

that y can be pluged back in to the OTHER equation to give you your x. once you have x and y put them in the form (x,y) and thats your answer

Answer 35

I'm just getting emotional

Answer 36

you got this! look up systems of linear equations in google. dont get discouraged! math makes alot more sense than emotions

Answer 37

http://www.purplemath.com/modules/systlin1.htm

Answer 38

I'm reading

Answer 39

I'm not good at math and I'm reminded of this constantly

Answer 40

I'm not good at this I'm sorry you're so nice for helping but I'm not good at any of this

Answer 41

This site is also rather good:
http://themathpage.com/alg/simultaneous-equations.htm

Answer 42

Thank you