Question

i need help solving this system by graphing??

Answer 1

\[\left\{ 2x+y=-7 \right\}\]

Answer 2

how do we graph in a text based area?

Answer 3

the best we can do is set up a table of solutions

Answer 4

\[\left\{ -3x-2y=14 \right\}\]

Answer 5

substitution works pretty well in this scenario:

can you solve the first equation for y?

Answer 6

yes

Answer 7

so, i subtract the 2y

Answer 8

-2x yes

Answer 9

ok

Answer 10

so i get

Answer 11

y = -7-2x; lets use this 'value' in the next equation

Answer 12

y=-2x-7

Answer 13

that ways good too ;)

Answer 14

doesnt the -2x come before because it has an x

Answer 15

it doesnt need to, but if you like it there; we can keep it there... it gets used up in the next one regardless

Answer 16

ok

Answer 17

-3x -2y = 14 - lets use that y value in this equation and solve for 'x'

Answer 18

and for the other one i subtract the -3x

Answer 19

To solve by graphing just means, draw the two lines and see where (if ever) they intersect.

Answer 20

lets keep the other one as is and use out y value in it

Answer 21

-3x -2y = 14

-3x -2(-2x-7) = 14 can you slove this ?

Answer 22

yes\

Answer 23

let me see you do it ;)

Answer 24

ok

Answer 25

ohh wait i dnt think i can solve this because it has two # before the paratheses

Answer 26

-3x -2(-2x-7) = 14

-3x +4x +14 = 14


-3x +4x +14-14 = 14-14

-3x +4x +0 = 0

the two numbers are seperate terms, they dont interfere with each other

Answer 27

oh ok

Answer 28

-3x +4x = 0
it just takes a little bit to be able to 'see' the problem :)


x = 0

this is our solution

Answer 29

wait how did u get the x to = 0

Answer 30

First step; plug in the value for y

-3 -2(-2x-7)= 14 ; now distribute the -2 thru the paranthesis

Answer 31

-3x +4x +14 = 14 do you see what i did there?

Answer 32

you did distributive property

Answer 33

yes, and since that was (-2) I used it in the process

Answer 34

-3x +4x +14 = 14 ; now we subtract 14 from both sides

-3x +4x +14-14 = 14-14

Answer 35

and got 0

Answer 36

correct; -3x +4x = 0

x = 0

Answer 37

but dnt we have to get the values bythemselfs first

Answer 38

by themselves? what are you refering to?

Answer 39

like -3x-4x=0

Answer 40

subtract then divide

Answer 41

-3x+4x = 0 combine like terms

-3x+4x = 1x right?

Answer 42

yes

Answer 43

then divide

Answer 44

yes, we do divide by 1 if we need to :)

then 1x = 0 ....x = 0

Answer 45

oh ok

Answer 46

in my multiple choices i do not have any one that has x=0

Answer 47

they all start with 4 or -4

Answer 48

and y has 1 or -1

Answer 49

we use 0 to find the value of y now and your choices are going to be (0,y)

Answer 50

but there is no choice for that with 0.

Answer 51

remember we found that y = -2x-7 right?

Answer 52

yes

Answer 53

unless you gave me the wrong equation information, this is what the answer needs to be :)

Answer 54

no its all correct

Answer 55

y = -2(0) - 7

y = -7

Answer 56

its jst that they are on top of eachother .

Answer 57

lets see if these answers work;

-3(0)-2(-7)=14

0+14=14

Answer 58

14=14

Answer 59

2x+y = -7

2(0) + -7 = -7

0 +-7 = -7

-7=-7

Answer 60

correct.

Answer 61

so we have the correct solution; but what are your answer to choose from look like?

Answer 62

(-4,-1) (4,1) (-4,1) (4,-1)

Answer 63

....... then either those go to a different problem; or they are simply wrong :)

Answer 64

i think they are wrong but idk.

Answer 65

there can only be one solution to lines that cross; it is the point we found (0,-7)

Answer 66

the problem is correct

Answer 67

ok well thanks.:)

Answer 68

if you ahve a teacher, bring it to their attention :)

Answer 69

yes i will do that

Answer 70

tag!!

Answer 71

Stop that.

Answer 72

lol tag

Answer 73

Really really annoying.