help with the elimination method? in math?

Question

ok well can you give me some examples of elimanation and tell me how you found the answers

2. 5s +2t=6
9s+2t=22

3. 3(2x+y)=15

5(3x-y)=1

Answer 1

give me an example and I will help you I love elimination method its sooo easyyy

Ok because the 2t are the same make one of them negative.
lets make the first row negative so multiply all by by -1.
That gives us
-2.5s-2t=-6
9s + 2t = 22

Now take out the 2t because you eliminated them

and add the -2.5s and the 9s = 6.5s
and -6+22= 16
now the equation looks like

6.5s = 16
Now divide both sides by 6.5
s = 2.46 roughly

now plug in the 2.46 for s in the second equation

9 (2.46) + 2t = 22
22.14 + 2t = 22
2t = -.14
divide both sides by 2

t = -0.7

Answer 2

2.
(1) 5s + 2t = 6
(2) 9s + 2t = 22
Notice that the coefficient of t is the same in both equations, and the coefficient of x in the 1st is less than the coefficient of x in the 2nd, so subtract (1) from (2).
4s = 16
s = 4
2t = 6 - 5*4
t = -7

3.
(1) 3(2x + y) = 15
(2) 5(3x - y) = 1
Divide (1) by 3, giving
(1) (2x + y) = 5
Divide (2) by 5, giving
(2) (3x - y) = 1/5
Add equations:
5x = 5 + 1/5
x = 26/25
y = 5 - 52/25 = (125 - 52)/25
y = 73/25

78/25 - 73/25 =? 1/5
5/25 = 1/5

Answer 3

Not sure if this is what you are talking about, but here is a good link:
http://www.teacherschoice.com.au/Maths_Library/Algebra/Alg_10.htm

Answer 4

2x+3y=6
4x-3y=6
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ADD
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2x+3y=6 (+) 4x-3y=6
6x=12
x=12/6
x=2
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2(2)+3y=6
4+3y=6
3y=2
y=2/3
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CHECK
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2x+3y=6
4x-3y=6
y=2/3
x=2
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2(2)+3(2/3)=6
4+2=6
6=6
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4(2)-3(2/3)=6
8-2=6
6=6
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DONE