SOLUTION: I need to know what are the steps to find out this question: x= 2y-1 3x-3y=9 My textbook is the Glencoe Alegebra 1 for Florida.

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Question 143375: I need to know what are the steps to find out this question:
x= 2y-1
3x-3y=9

My textbook is the Glencoe Alegebra 1 for Florida.
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
x=2y-1 NOW REPLACE X WITH (2Y-1) & SOLVE FOR Y IN THE SECOND EQUATION.
3x-3y=9
3(2Y-1)-3Y=9
6Y-3-3Y=9
3Y=9+3
3Y=12
Y=12/3
Y=4 ANSWER.
X=2*4-1
X=8-1
X=7 ANSWER.
PROOF:
3*7-3*4=9
21-12=9
9=9