Question 854535: Elimination Method Example:
Equation 1: 2x-y=4
Equation 2: 2x+5y=16
x will be eliminated
equation 2 – equation 1
2x+5y=16
-) 2x-y=4
6y=12
y=12
Substitute y=2 in equation1
2x-y=4
2x-2=4
2x=6
x=3
Answer: x=3, y=2 or (3, 2)
My teacher says:
In order for elimination to work you must have a term that has the same number, variable and opposite signs. You eliminated x by using subtraction, however, in order to use subtraction you must distribute the (-) through the entire problem. How would you fix this in your example? Give the steps involved in fixing your elimination example.
Answer by Fombitz(32388) (Show Source):
You can put this solution on YOUR website! You can multiply by (-1) and then add but this is the same thing as subtraction, you just distribute the (-1) during the multiplication.
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