Question

if 2x+y=8 and x-y = 1 then y = ?
Please help :(
There are multiple choices for this, but I don't want to plug in numbers (Because I want to know the real technique), is there a way to answer this algebraically? Please give me detailed instructions I will give you a shiny medal :D

Answer 1

Wait a minute, is there no solutions for why? because that's one of the options

Answer 2

2x+y=8
x-y=1 multiplie by -2 and will get -2x +2y = -2

2x+y=8
-2x+2y=-2
---------- assume the same terms
0 3y = 6

3y = 6 divide both sides by 3

y = 6/3

y = 2

hope this will help you

Answer 3

ok. ?

Answer 4

Ohmigosh thank you so much!

Answer 5

do you understand it now sure ?

Answer 6

So we just put it on top of each other and cancel out? Sorry I was helping someone else with us civic homework

Answer 7

so you can solving system of equations using elimination method or substitution method - do you know these ?

Answer 8

we want to cancel out the x first right? So we multiple by the coefficient of 2 (but turn it to negative 2 to cancel out right)?

Answer 9

here above i ve used elimination method because there are

2x +y = 8 and
x -y = 1 do you see that in this present case than we assume the same terms will cancel out the y but because we need to solve it for y so not is right cancel out and in this way we need multiplie second equation by -2 to get -2x and 2x from the first equation and -2x what we get in second equation will cancel out and will remain just the terms of y

ok. ?

Answer 10

yes exactly so this mean that you understood it right sure

Answer 11

Ooooh, I see what you mean now!!! :DDD

Answer 12

-2x +2y = -2 so 2y not just y

Answer 13

but I got 2y = 6 so 6/2 = 3 which means y = 3? Ahh I see what I did wrong

Answer 14

hi.. lol

Answer 15

ohmigosh thank you so much for being so patient and helping me with my math! <3 :DDD

Answer 16

can you help me now? @Lacris

Answer 17

oh my gosh you came all the way to my math questions?

Answer 18

lol yea

Answer 19

jhonny do you know about the checks and bills law?

Answer 20

lol no i want you to help me..

Answer 21

I tried to explain, do you understand it volley?

Answer 22

can we talk about this in my post lol

Answer 23

@Lacris np was my pleasure and anytime just tag me there

good luck

bye bye

Answer 24

awww thank you :D!!

Answer 25

anytime