SOLUTION: Identify three methods you can use to solve a sysytiem of equations and explain when to use each method then write example systems that illustrate when to use each method.

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Question 174464This question is from textbook Algebra 2, Texas Edition
: Identify three methods you can use to solve a sysytiem of equations and explain when to use each method then write example systems that illustrate when to use each method. This question is from textbook Algebra 2, Texas Edition

Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
SUBSTIUTION: USE WHEN ONE EQUATION HAS NO INTEGER.
Y=3X
2Y-8=2X
2*3X-8=2X
6X-8-2X=0
4X=8
X=8/4
X=2 ANS.
Y=3*2
Y=6 ANS.
PROOF:
2*6-8=2*4
12-8=4
4=4
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ADDITION: USE WHEN ONE UNKNOWN IS A MULTIPLE OF THE SAME UNKNOWN IN THE OTHER EQUATION.
Y-3X=0 MULTIPLY THIS EQUATION BY -2 & ADD
2Y-2X=8
-2Y+6X=0
2Y-2X=8
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4X=8
X=8/4
X=2
Y-3*2=0
Y-6=0
Y=6
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CROSS MULTIPLICATION: USE WHEN THERE ARE FRACTIONS INVOLVED.
Y/4X=3/4
4Y=12X
Y=12X/4
--------
3Y/3X=3
3(12X/4)/3X=3
(36X/4)/3X=3
36X/4=9X
36X=36X