SOLUTION: If x - 3y = 8 and y = 2x - 1 then x=

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Question 316764: If x - 3y = 8 and y = 2x - 1 then x=
Found 2 solutions by jim_thompson5910, moshiz08:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Hint: Plug y+=+2x+-+1 into x+-+3y+=+8 to get x+-+3%282x-1%29+=+8

Answer by moshiz08(60) About Me  (Show Source):
You can put this solution on YOUR website!
Let's plug y=2x-1 into x+-+3y+=+8.
Then this becomes
+x+-+3%282x-1%29+=+8+
Distributing the 3 gives
+x+-+6x+%2B+3+=+8+
Combining like terms gives
+-5x+%2B+3+=+8+
Subtracting 3 from both sides gives
+-5x+=+5+
Dividing by -5 gives
+x+=+-1+

Now we check: since y = 2x -1, plug in x=-1 to get y = 2(-1) - 1 = -3. Then we check that x - 3y = (-1) - 3(-3) = 8, so this works.