SOLUTION: i) Sketch on the same diagram the graphs of y = |2x + 3| and {{{y = 1 - x}}}. ii) Find the values of x for which x + |2x + 3| = 1 *Please answer as soon as possible and als

Algebra ->  Graphs -> SOLUTION: i) Sketch on the same diagram the graphs of y = |2x + 3| and {{{y = 1 - x}}}. ii) Find the values of x for which x + |2x + 3| = 1 *Please answer as soon as possible and als      Log On


   



Question 470220: i) Sketch on the same diagram the graphs of y = |2x + 3| and y+=+1+-+x.
ii) Find the values of x for which x + |2x + 3| = 1

*Please answer as soon as possible and also please explain in details how your sketch the graph. :) =)

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
You can think of +y+=+abs%28+2x+%2B+3+%29+ as
the same as +y+=+2x+%2B+3+, except that
whenever y is negative, you just ignore the
minus sign and make y positive.
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Note that y+=+0 when +x+=+-3%2F2+, since
+y+=+abs%282%2A%28-3%2F2%29+%2B+3%29+
+y+=+abs%28-3+%2B+3%29+
+y+=+0+
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When +x+%3C+-3%2F2+, then +y+=+2x+%2B+3+
becomes negative, but you just ignore the minus sign.
Graphically, that amounts to reflecting the line
about the y-axis so that y ends up positive
-----------
Here's the graph so far:
+graph%28+400%2C+400%2C+-10%2C+10%2C+-10%2C+10%2C+abs%282x+%2B+3%29+%29+
and, adding +y+=+1+-+x+,
+graph%28+400%2C+400%2C+-10%2C+10%2C+-10%2C+10%2C+abs%282x+%2B+3%29%2C++1+-+x+%29+
Now I want all x for which +x+%2B+abs%282x+%2B+3%29+=+1+
Now subtract x from both sides
+abs%282x+%2B+3%29+=+1+-+x+
This is just the solutions, or intersections of the graphs.
---------------------
The reflected part of +y+=+2x+%2B+3+ will have slope = -2
and the y-intercept is +y+=+-3+ so the equation is y+=+-2x+-+3+
So I want the solutions to:
(1) +y+=+2x+%2B+3+
(2) +y+=+-2x+-+3+
(3) +y+=+1+-+x+
(3) and (1):
+1+-+x+=+2x+%2B+3+
+3x+=+-2+
+x+=+-2%2F3+
and
+y+=+1+-+x+
+y+=+1+-%28-2%2F3%29+
+y+=+5%2F3+
(-2/3, 5/3) is a solution
---------------------
(3) and (2):
+1+-+x+=+-2x+-+3+
+x+=+-4+
and
+y+=+1+-+x+
+y+=+1+-%28-4%29+
+y+=+5+
(-4, 5) is a solution
The answer to (II) is x+=+-2%2F3
and x+=+-4