Question

Solve by elimination method:
9x-9y=36
7y-3x=-14

Another problem:

0.3x-0.2y=4
0.4x+0.5y=1

Answer 1

Hello i will help you today

Answer 2

thanks

Answer 3

.3x - .2y = 4 -->(1)
.4x + .5y = 1 -->(2)

(1)x5 you get 1.5x - y = 20
(2)x2 you get .8x + y = 2

Add up these two, you get 2.3x = 22
x = 220/23
Substitute x back into any equation, you get y = -130/23

and

5x +3y = -11 -- (1)
7x - 2y =19 -- (2)

(1)x2 you get 10x + 6y = -22
(2)x3 you get 21x - 6y = 57

Add the two, you get 31x = 35
So x = 35/31
Substitute x back into any equation, you get y = 172/31

and

9x - 9y =36 -- (1)
7y - 3x = -14 -- (2)

(2)x3 you get -9x + 21y = -42

Add this to (1), you get 12y = -6, so y = -1/2
Substitute y back into any equation, you get x = 7/2

Answer 4

tell me if that helps at all

Answer 5

the one problem i think you wrote wrong it was supposed to be 5x+2y=-7
7x-3y=11

Answer 6

ok i am srry hold on

Answer 7

okay

Answer 8

wait nevermind i wrote it wrong

Answer 9

5x+2y=-13
7x-3y=17

Answer 10

ok here we go

9x-9y=36 => x - y = 4 => x = 4+y
7y-3x=-14 => 7y - 3(4+y) = -14

7y - 12 - 3y = -14
4y = -2
y = -1/2
x = 4-1/2 = 7/2

(x,y) = (7/2, -1/2)

Answer 11

would you mind helping me on a few more

Answer 12

no i would love to

Answer 13

5x+2y=-13
7x-3y=17

0.05x+0.25=11
0.15x+0.05y=12

Answer 14

Substitution method:

7m+n=46
m-3n=16

Answer 15

Im really having trouble with the substitution one

Answer 16

ok

Answer 17

umm i cant to seem to get this won hold on and i am going to have some won help if that is ok with you

Answer 18

well what would the elimination problems be i sent you

Answer 19

ok is this it tight here

Start by multiplying the first equation by 2, and the second by 3:

10x + 6y = -22
21x - 6y = 39

Now add the two together, you y's cancel out , "eliminating" it.

21x = 17

x = 17/21

5x + 3y = -11
5(17/21) + 3y = -11
85/21 + 3y = -11
85 + 63y = -231
63y = -146
y = -146 / 63

Answer 20

okay thanks how about 0.05x+0.25y=11
0.15x+0.05y=12

Answer 21

ok here we go

5x + 25 y = 1100
15 x + 5 y = 1200

- 15x - 75y = - 3300
15x + 5y = 1200-----------ADD

- 70 y = - 2100

y = 30

5x + 750 = 1100
5x = 350
x = 70

x = 70 , y = 30

Answer 22

wow thanks your like a lifesaver haha

Answer 23

np i love to help

Answer 24

5x+5y=-11
7x-3y=17

Answer 25

this is done by elimination

Answer 26

i am on it

Answer 27

thanks!!!

Answer 28

5x+5y=-11 multiply by 2 ==> 10x + 10y = -22
7x-2y=17 multiply by 5 ===> 35x - 10y = 85
Add the two equations:
10x + 35x = -22+85
45x = 63
x = 63/45 = 7/5
substitute into original equation:
5(7/5) + 5y = -11
5y = -18
y = -18/5

Solution set: (x,y) = (7/5, -18/5)

ok do this help

Answer 29

it told me i was wrong

Answer 30

ummm that is weird

Answer 31

what r ypu working on so i know i might know why

Answer 32

its a math program and I have to enter the answers in and it lets me know if im wrong or not then submits it to my teacheer part of my homeschool

Answer 33

ok i do home schooling to i think i know what programe you talking about

Answer 34

okay

Answer 35

umm that i weird i woundr were we went wrong

Answer 36

i dunno im trying to figure it out too

Answer 37

Ill rewrite the problem

Answer 38

5x+5y=-11
7x-3y=17

Answer 39

ok

Answer 40

ok i think i got it

Let's just multiply everything by 100 to eliminate the decimals.
5x + 25y = 1100
15x + 5y = 1200

Multiply the first equation by 3
15x + 75y = 3300
15x + 5y = 1200

Subtract the second equation from the first
70y = 2100
7y = 210
y = 30
15x + 5(30) = 1200
15x + 150 = 1200
15x = 1200 -150
15x = 1050
x = 1050/15 = 70

Let's check in the original equations.
0.05(70) + 0.25(30) = 3.50 + 7.50 = 11 check.
0.15(70) + 0.05(30) = 10.50 + 1.50 = 12 check.
8 months ago Report Abuse

Answer 41

srry about the 8 month ago i did that srry

Answer 42

its okay

Answer 43

i was working on something els and it got out up there

Answer 44

did you see the word problem i posted could you help me with that

Answer 45

did you ever figure out that one problem for me