SOLUTION: Solve using either substitution or addition method. Tell which method was used? 3y=x+5 -3x+8y=8

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Question 171044: Solve using either substitution or addition method. Tell which method was used?
3y=x+5
-3x+8y=8
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
3y=x+5 multiply by -3 & add.
-3x+8y=8
3x-9y=-15
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-y=-7
y=7 ans.
3*7=x+5
21=x+5
x=-21-5
x=-26 ans.
Proof:
-3*-26-9*7=-15
78-63=-15
-15=-15