Question

Help asap please?
I'm doing Algebra 2, when you're solving a system by substitution.. For example my problem is
2x+y=-11
3x-4y=11
Could somebody walk me through it? Don't give me the answer.

Answer 1

to do this by substitution you first want to get one of the equations as y =
so pick the one that's easiest to do that, and tell me what you get :)

Answer 2

Okay, I do the first one... 2x+y=-11 and i subtract y from each side and get 2x=-11-y

Answer 3

From first equation find value of y , that is solve for y

so we will get y = -11 - 2x now just plug this value of y in second equation
that is 3x - 4(-11 - 2x) = 11 now just simplify it
use distributive property
a*(x+y) = a*x + a*y
& find value of x & then put this value of x in any equation & find y

Answer 4

Okay one second, tgawade

Answer 5

Ok

Answer 6

@tgawade x=-3 and y=-5 ???

Answer 7

yes, that is correct ^_^ good job! :D

Answer 8

Can you help me with one moe @jigglypuff314

Answer 9

Sure :)

Answer 10

Took my words back.

Good work @tgawade and @jigglypuff314 .

Answer 11

Okay, on this one I have to solve the system using elimination. It's
2x+6y=-12
5x-5y=10

Answer 12

well 5x - 5y = 10 can be reduced by dividing through by 5 right?
could you do that?

Answer 13

divide each side by 5 ?? under x or y

Answer 14

both
like if you divide through by 2 for 2x+6y=-12
you would get x + 3y = -6

Answer 15

okay one second. i'll divide by 5

Answer 16

x-y=2?

Answer 17

correct :)
so now you have
x + 3y = -6
x - y = 2 and you see how the x's are lined up? you can then subtract
so...
x + 3y = -6
-(x - y = 2) (don't forget to distribute the minusing)

Answer 18

okay one minute!!

Answer 19

x=-9 y=1 ??? @jigglypuff314

Answer 20

hmmm
well from
x + 3y = -6
-(x - y = 2) it would be subtracted like
-------------
4y = -8 do you see how I got that? could you go on from there? :)

Answer 21

OH so x=0 and y = 2 !! @jigglypuff314

Answer 22

Correct! :D

Answer 23

Woot ! :) Thank you so much ! If I have any other questions , I'll let you know ! Will you be on for awhile ?

Answer 24

I might have to go to dinner soon, but I'll be around afterwards :)

Answer 25

Wait... (0,2) isn't an answer ....
My answers are
(2,1)
(0,-2)
(-2,0)
(1,2)

Answer 26

Nevermind, it would be (0,-2) I forgot the 8 was a negative!

Answer 27

do you have time for one more ?

Answer 28

yeah sure, post it in another question :)