Question

Help me out with this question?

Answer 1

So i multiply the y by 4 right?

Answer 2

cam you isolate y from first equation ?
hint
subtract 2x from both sides...

Answer 3

Ohh...

Answer 4

multiplying by 4 , will become the method of elimination :)

Answer 5

so i got y=-1 and x- 4y=11

Answer 6

opps i mean -11

Answer 7

y=-1 ?? how ?
2x+y=-11

so
y = -11-2x
got this ?

Answer 8

okay and the other equation is -4y=11-2x

Answer 9

i never asked to isolate y from other equation :P
but oh, well, you can plug in the y, from 1st equation into other!

plug in y=-11-2x in 2nd equation
what u get ?

Answer 10

how the frick do i plug in that huge equation into the other one

Answer 11

lol, quite easy, if you try :)

\(\huge y=-11-2x \:\: in \quad 3x-4y =11 \\ \implies \huge 3x-4(-11-2x)=11 \)

got this ?

Answer 12

ok but there is an x in that parenthesis how ughhh im so dumb i hate math :(

Answer 13

the term
-4(-11-2x) is making you feel dumb ??
lets make this term feel dumb instead :P

distribute -4 to each(both) term!
like a(b+c) = ab+ac
ry ?

Answer 14

*try

Answer 15

ok i got 3x + 44 + 8x =11

Answer 16

see! how simple it was :D you are absolutely correct :)
now find 'x' from that...
3x+8x = ... ?

Answer 17

i did 11x + 44 =11

-44 on each side so x =33

Answer 18

i mean -33

Answer 19

that isn't even one of the answers :S

Answer 20

11x +44 =11
so,
11x = -33
so, x = ... ?

Answer 21

-33 is 11x, not x :P

Answer 22

divide both sides by 11

Answer 23

- 3 !!!!!

Answer 24

correct! :D

Answer 25

so which equation do i plug -3 in for

Answer 26

ideally, we need not find the 'y'
but just make sure the 'y' you get is correct

put x=-3 in any equation
y=-11-2x

Answer 27

y=-11-2(-3) = ... ?

Answer 28

-5 :D

Answer 29

you got it ;)

Answer 30

help me out with one more??

Answer 31

only one?

Answer 32

as many as you need :)

Answer 33

You're a sweetheart :D

Answer 34

oh, am i ?? i thought the same thing bout u :

Answer 35

multiply first equation by -3
what uget ?

Answer 36

you know why i am multiplying 1st equation by -3 ?

Answer 37

yes so it can equal 9 :D

Answer 38

-9x - 6y = -36

Answer 39

ok, you multiplied by 3, right ?
even that will do :)
now add both the equations :)

Answer 40

is it -27

Answer 41

what is -27 ?

Answer 42

no wait -45

Answer 43

add these 2 equations
-9x - 6y = -36
9x +6y=-9

Answer 44

dont the 9x and 6y cancel out and that's left with -45

Answer 45

-45 is correct right side!
whats on the left side ?

Answer 46

i thought they cancel out

Answer 47

or is it 18x + 12y =-45

Answer 48

yeah, and what remains ?
like whats 9x-9x = ... ?

Answer 49

x ??

Answer 50

its NOT 18x + 12y

Answer 51

ok, whats 9-9 = ... ?

Answer 52

0 !

Answer 53

yes
so 9x-9x = 0

Answer 54

left side = 0
0 =-45

Answer 55

is that even possible ?

Answer 56

no so its no solutions right??

Answer 57

absolutely :)

Answer 58

thanks, what about this one :)

Answer 59

do i add or subtract x?

Answer 60

just add the 2 equation...

Answer 61

0 = 0 so that means infinite right? :)

Answer 62

oh, you are so smart! :D

Answer 63

correct :)

Answer 64

says you i bet you're in like a super smart math that i dont even know about

Answer 65

my field of study is not math, its electronics, but we study one subject of math each year, not too high level though :)
i won't consider myself super smart :P

Answer 66

Oh i see. So do you make electronics or fix them and stuff?

Answer 67

nopes, not fix them, just understand how they work

Answer 68

oh i see :) can you help me out with this last one?

Answer 69

sure

Answer 70

thanks lovely

Answer 71

know the method of elimination ?

Answer 72

kind of

Answer 73

do u know that in elimination method, we try to make the co-efficient of any one variable, same in both equations......

Answer 74

so. lets start,
multiply 1st equation by 5
what u get ?

Answer 75

and ask me if you don't know "why" i am doing so

Answer 76

its bc you need the x's to be the same so first one is 10x+30y=60 and second equation is 10x - 25y=50

Answer 77

-12 * 5 = -60
in the 1st equation

what did u do with the 2nd one???

Answer 78

wai tis the second one 10 * 5 =50

Answer 79

10x+30y=-60 right ?

now you had to multiply 2nd equation by "2" to make that 10x....

Answer 80

not by 5

Answer 81

oh so 10 * 2 = 20

Answer 82

yeah, tell me what u get entire 2nd equation?

Answer 83

10x + 2y = 20

Answer 84

2y ???

-5y*2 = -10y , isn't it ?

Answer 85

IDK LOL so wait the second equation is -5y * 2 = -10y

Answer 86

how can there be two y's

Answer 87

no i meant,
5x-5y=10

multiplying this by 2, we get
10x-10y =20

got this ?

Answer 88

oohhh now i get it

Answer 89

cool :)

so,
10x+30y=-60
10x-10y =20

just subtract the 2nd equation from 1st eqation!
and note that 'x' gets eliminated :)

Answer 90

:( i got -60 im doing something wrong

Answer 91

-60 for what ?

Answer 92

x

Answer 93

but the 'x' gets cancelled
1x-10x = 0

Answer 94

****10x-10x=0