Question

Urgent! Will fan and medal!!

x + y = 27
4x + 1y = 45

Whats the solution to the equations and how did u get it?

I know about substitution and elimination but its not working out... Help...??

Answer 1

What would you like to use?

Answer 2

I suggest elmination

Answer 3

Ok elimination then

Answer 4

Keep this in mind: OPPOSITES CANCEL
whats the opposite of 4 ?

Answer 5

-4

Answer 6

I second elimination method.. works best.

Answer 7

\[-4(-x + y = 27)\]
distribute

Answer 8

4x + -4y = 27 ?

Answer 9

close but you forgot to distribute the -4 to the 27
what's -4 x 27?

Answer 10

i accidently slipped in the -

Answer 11

-4(x + y = 27)
-4 * x = ?
-4 * y = ?
-4 * 27= ?

Answer 12

-108

Answer 13

we are distributing the -4 all over the first equation.

Answer 14

and yes -4 x 27 is -108 :)

Answer 15

-4x
-4y
-108

Answer 16

correct so your new first equation is

-4x-4y=-108

Answer 17

ill let doll finish :)

Answer 18

so now we have

-4x-4y=-108
4x + 1y = 45

Answer 19

what do we need to do to get rid of the x?

Answer 20

lol @pooja195 thanks for ur help

Answer 21

inverse? @UsukiDoll

Answer 22

umm .. not quite.. our goal is to eliminate a variable.

Answer 23

-4x-4y=-108
4x + 1y = 45

so what do we need to do to get rid of this x??
we have -4x and 4x... maybe adding these equations together might work

Answer 24

ooh right so it would be: x - 5y = -63?

Answer 25

hmm .... only the right hand side of the equation is correct

Answer 26

ok... let's think finance for a bit
you bought pens for $4, you paid $4
-4x+4x = ?

Answer 27

0x or just x

Answer 28

0x is fine... but 0 times x => 0

Answer 29

ohhhh

Answer 30

ok so we got rid of the x... now for the y we have -4y+1
it's like you are trying to buy pens for $4, but all you have is a dollar. How much more money do you need?

Answer 31

oops I meant -4y+1y

Answer 32

3 dollars

Answer 33

so -3y

Answer 34

yes! so -4y+y = -3y

Answer 35

so now we have -3y=-63

Answer 36

all we need to do is isolate y ... how do we do that?

Answer 37

in other words... we need y by itself.. no numbers no variables..

Answer 38

divide -63/-3=21

Answer 39

mhm so y = 21

Answer 40

the second part is finding x.. luckily it's easier.. we just need to subsitute y = 21 in one of the original equations. I highly suggest the easier ones

Answer 41

x + y = 27

Answer 42

ok: x + 21 = 27
x= 6

Answer 43

yes

Answer 44

so x =6 and y =21, but do these values work for the other equation. I know it does for the first equation because
x+y=27
6+21=27
27=27

Answer 45

4x + 1y = 45
so plug in x = 6 and y =21

Answer 46

4*6=24 1*21=21
21+24=45!!!

Answer 47

yes

21+24=45
45=45
so we have found our x and y values.

Answer 48

alternatively you can choose to eliminate the y first and solve for x

Answer 49

x + y = 27
4x + 1y = 45


-x-y=-27
4x+y=45

3x = 18
x=6

6 + y = 27
-6 -6
y=21

Answer 50

^_^ I got the same values by eliminating the y first
and my steps were shorter too.

Answer 51

Thanks a million @UsukiDoll you are the best!!!!! you really helped me

Answer 52

I've noticed that through inspection I had two one y's so I figured if I make one of the y's negative I can solve this quickly.

Answer 53

:D you're welcome

Answer 54

gnite tysm