SOLUTION: 2a-4b=6 and -a+2b=-3 solve using substituiton

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Question 829302: 2a-4b=6 and -a+2b=-3 solve using substituiton
Answer by erica65404(394) About Me  (Show Source):
You can put this solution on YOUR website!
2a-4b=6
-a%2B2b=-3
solve one of the equations for a.
2a-4b=6
2a-4b%2B4b=6%2B4b
2a=4b%2B6
2a%2F2=%284b%2B6%29%2F2
a=2b%2B3
You can use the substitution method by replacing any a with 2b+3 since a is equal to 2b+3.
-a%2B2b=-3
-%282b%2B3%29%2B2b=-3
-2b-3%2B2b=-3
-3=-3
whenever you are left without the variable, and the statement is true, ie -3 is equal to -3, then it means infinite solutions. if it were untrue, ie 5 is equal to 2, then it would be no solution. Since -3=-3, b=any number. And since b is any number, a would also be any number.
answer: a=any number, b=any number
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