SOLUTION: Find the ares bounded by the graphs of: Y=x+4, Y=-3x, and the y-axis

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Question 431945: Find the ares bounded by the graphs of:
Y=x+4, Y=-3x, and the y-axis
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Here's the graph:
+graph%28+400%2C+400%2C+-6%2C+6%2C+-6%2C+6%2C+x+%2B+4%2C+-3x%29+
I notice that +y+=+-3x+ goes through the origin,
because when x=0, y=0.
And, y+=+x+%2B+4 intersects the y-axis at y=4
since +y+=+0+%2B+4+.
------------------
Using substitution,
y+=+x+%2B+4
-3x+=+x+%2B+4
-4x+=+4
+x+=+-1
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and
y+=+x+%2B+4
y+=+-1+%2B+4
y+=+3
The lines meet at (-1,3)
The area is %281%2F2%29%2Ab%2Ah
b would be the side on the y-axis, 4
The height would be the shortest distance
from (-1,3) to the y-axis, which is 1
(don't use (-) signs when finding distance)
So the area is %281%2F2%29%2A4%2A1+=+2