OK so I need help with my homework I don't get how to do it
:(
4x+3y=1
x=1-y

so far I have

4(1-y)+3y=1
4-4y+3y=1
-1/-1 =1/-1
x=-1
1--1
y=-2 (-1,-2)

do I have it right or is it wrong and if its wrong show me what step I did wrong and thank you
:D

Hehe, Lets see if I can help you. This subject is one of my strong ones ;)

4x + 3y = 1 (If x = 1 - y ) then,

First Step: 4( 1 - y ) + 3y = 1.

Second Step: 4 - 4y + 3y = 1.

Third Step (group all x's to one side, and all non x's to another): -4y + 3y = -4 + 1.

Fourth Step: -y = -3, but you want to find positive y not negative y. So it ends up being y = 3.

Fifth Step: Plug in the answer you got to find why in the original problem to find x.

Sixth Step: 4x + 3(3) = 1.

Seventh Step: 4x + 9 = 1. Then, we group non variables on one side and the numbers w/ variables on the other.

Eighth Step: 4x = -9 + 1. Therefore, 4x = -8.

So, x = -8/4

Answers are: y = 3 , x = -2.

P.S. - Sorry for all the steps, I needed to show you the EASIEST WAY to find what x and y are and in the most precise way. Hope this helped!

thanks it helped no I have a different problem its
2x-y=6
-x+y=-1:confused:

Quote:

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Originally Posted by Ninjagirl14

ok so i need help with my homework i dont get how to do it
:(
4x+3y=1
x=1-y

so far i have

4(1-y)+3y=1
4-4y+3y=1
-1/-1 =1/-1
x=-1
1--1
y=-2 (-1,-2)

do i have it right or is it wrong and if its wrong show me what step i did wrong and thank you
:D

---

::cool:

Its correct good job

Make sure to write out the whole problem if you have not, it's a little confusing if you have only one or two problems.

So, what you said was 2x - y = 6. And -x + y = -1.

It would make most sense that in the ( -x + y = -1 ), -x would equal 5 and y would equal 4. Therefore, in the (2x - y = 6), x would equal 5 and negative y would equal 4.

Checking: 2(5) - 4 = 6 --> 10 - 4 = 6. YES.

Checking: -x + y = -1 --> -5 + 4 = -1. YES.





Here's a helpful tip: In algebra, If you want your answer of -x to be positive, than you would write (1) -x = -5, since the two negatives cancell each other out to make it positive.

If you want the answer of x to be negative, than you would write (1) x = -5 , (2) -x = 5.

It is WRONG to say that negative x equals negative 5 -->(-x = -5). This turns out to be positive x equals positive 5 (x = 5).

Another Solution is: if you wrote

2x - y = 6
- x + y = -1

then it would be

x = 5. Than Plug in the answer for x in the 2x - y = 6 problem. So 2(5) - y = 6. Therefore, -y = -10 + 6. Last, -y = -4, so negatives cancell and it will be y = 4.

I think you needed the ANSWER TO THIS ONE. FORGET ABOUT THE OTHER ONE That's FOR A MORE COMPLICATED PROB. ;)

HOPE THIS HELPED. BTW the first problem was wrong but I corrected it for you.

thanks =D

x+y=-9
5x-2y=32

how to use elimantion to solve this