SOLUTION: Point of intersection of the lines whose equations are y=-1/2x+3 and y=2x+8

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Question 281605: Point of intersection of the lines whose equations are y=-1/2x+3 and y=2x+8
Found 2 solutions by josmiceli, richwmiller:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
I would get these both into the standard form
and solve simultaneously
y+=+%28-1%2F2%29x+%2B+3
%281%2F2%29%2Ax+%2B+y+=+3
(1) x+%2B+2y+=+6
and
y+=+2x+%2B+8
(2) 2x+-+y+=+-8
Multiply both sides of (2) by 2
and add (1) and (2)
(1) x+%2B+2y+=+6
(2) 4x+-+2y+=+-16
5x+=+-10
x+=+-2
and, substituting,
(1) -2+%2B+2y+=+6
2y+=+8
y+=+4
The lines intersect at (-2,4)
here's the plot:
+graph%28+500%2C+500%2C+-6%2C+8%2C+-6%2C+8%2C+%28-1%2F2%29%2Ax+%2B+3%2C+2x+%2B+8%29+

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
I would set them equal to each other
-1/2x+3=2x+8
add 1/2x to both sides
3=2.5x+8
subtract 8 from both sides
-5=2.5x
divide by 2.5
-2=x
y=-1/2x+3 and y=2x+8
y=2x+8
y=2*(-2)+8
y=-4+8=4