SOLUTION: If three straight lines x+2y-1=0 >>> x-y+2=0 >>> ax-y+3=o meet at one point then a=

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Question 878342: If three straight lines x+2y-1=0 >>> x-y+2=0 >>> ax-y+3=o meet at one point then a=
Found 2 solutions by Fombitz, ewatrrr:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Find where the first two lines meet.
Subtract the first equation from the second.
x-y%2B2-x-2y%2B1=0
-3y%2B3=0
-3y=-3
y=1
Then,
x-y%2B2=0
x-1%2B2=0
x%2B1=0
x=-1
The first two lines meet at (-1,1).
Now solve for a.
a%28-1%29-1%2B3=0
-a%2B2=0
-a=-2
highlight%28a=2%29
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Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi

-.5x + .5 = x+2,  x = -1 and y = 1

y =  ax+3

1 = -a + 3

a = 2

y = 2x+3 (Purple Line)