SOLUTION: ordered pairs .3x-0.2y=4 .4x+0.3y=49/23 my confusion lies on what I should be plugging in, In class I am learning the three different methods substiituion, elimination and gr

Algebra ->  Systems-of-equations -> SOLUTION: ordered pairs .3x-0.2y=4 .4x+0.3y=49/23 my confusion lies on what I should be plugging in, In class I am learning the three different methods substiituion, elimination and gr      Log On


   

Question 414191: ordered pairs
.3x-0.2y=4
.4x+0.3y=49/23
my confusion lies on what I should be plugging in, In class I am learning the three different methods substiituion, elimination and graphing. Well I am totally confused on all of them and do not understand what numbers I should be using to solve. Thank you for any help
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
.3x-0.2y=4
.4x+0.3y=49/23
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Multiply thru 1st by 10
Multiply thru 2nd by 23
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3x - 2y = 40
9.2x+6.9y = 49
----
Multiply thru 2nd by 10
3x - 2y = 40
92x + 69y = 490
----
Multiply thru 1st by 69
Multiply thru 2nd by 2
-----
207x - 138y = 2760
184x + 138y = 980
----------------------
Add and solve for "x":
391x = 3740
x = 220/23
-----
Solve for "y":
3x - 2y = 40
3(220/23) - 2y = 40
660/23 - 2y = 40
---
330/23 - y = 20
y = (330/23)-20
y = -130/23
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Cheers,
Stan H.
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