Question

solve the system by the elimination method
5x+5y=-11
7x-2y=19

Answer 1

multiply first equation by 7 and second by -5 and the add the resulting equations and tell me what u get....

We will proceed from there

Answer 2

@purplec
pls do not provide the solution otherwise lizzy will not learn how to do this kind of sums on her own

Answer 3

okay

Answer 4

thanks!!

Answer 5

@lizzy
pls do as i suggested and tell me what u get......

Answer 6

hey lizzy???????????

Answer 7

10x+5y=-11
21x-6y=19

Answer 8

this is wrong, u have to multiply all terms by the number
try again.....
multiply the first equation one by 7 and second equation by -5

Answer 9

I thought it was by two and three

Answer 10

why??? our aim is to make the coefficients of x same (we can even make coefficients of y equal if we want...)

Answer 11

35x+35=-11
-35x++-10y=19

Answer 12

someone elese on here told me to multiply first line by 2 and second by 3. is this wrong???

Answer 13

I am so confused now..OMG

Answer 14

I have nine problems like this and i do not understand how to do them..can u help me

Answer 15

see it might have been for some other sum.....
by the way, do you hv a SKYPE account????
If yes, v can have voice chat n things will move faster...

Answer 16

what's that SKYPE account???

Answer 17

is is a downloadable program which u can download from SKYPE.COM website and then u and i can chat over the net...

Answer 18

my SKYPE id is hakki.singh

Answer 19

why we just can't chat here??

Answer 20

ok here we hv to type, that takes time...

Answer 21

see for such "elimination method" questions, we have to try to make the coefficients of either x or y equal so that we can eliminate one variable..

Understood...

Answer 22

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

so in this case we multiply (1) by 7 and (2) by -5, to get

35x + 35y = -77 ---------(3)
-35x + 10y = -95 ---------(4)

got it???

Answer 23

Now if we add (3) and (4) we get
45y = -172
y = -172/45

Answer 24

now put y = -172/45 in (1)

-172
5x + 5*------- = -11
45
172
5x - ----- = -11
9
172
5x = -11 + ------
9
-99 + 172
5x = -----------
9
73
x = --------
45

Answer 25

so final solution is x = 73/45 and y = -172/45