SOLUTION: {{{2x - 3x^(1/2) + 1 = 0}}}

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Question 70150This question is from textbook College Algebra Essentials
: 2x+-+3x%5E%281%2F2%29+%2B+1+=+0 This question is from textbook College Algebra Essentials

Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!


2x+-+3x%5E%281%2F2%29+%2B+1+=+0

Two ways to solve it. Pick whichever one
is the method you are studying now.

Method 1.

Change x%5E%281%2F2%29 to sqrt%28x%29

2x+-+3sqrt%28x%29+%2B+1+=+0

Isolate the radical term

2x+%2B+1+=+3sqrt%28x%29

Square both sides of the equation:

%282x+%2B+1%29%5E2+=+%283sqrt%28x%29%29%5E2

%282x+%2B+1%29%282x+%2B+1%29+=+9x+

4x%5E2%2B2x%2B2x%2B1+=+9x+

4x%5E2%2B4x%2B1+=+9x

Get 0 on the right by subtracting 9x 
from both sides:

4x%5E2-5x%2B1=0

Factor the left side

%284x-1%29%28x-1%29=0

Setting 4x-1=0 gives x=1%2F4

Setting x-1=0 gives x=1

Both answers check.

---------------------------------------------

Method 2.

2x+-+3x%5E%281%2F2%29+%2B+1+=+0

Let x%5E%281%2F2%29+=+w

Then squaring both sides of that we have

   x+=+w%5E2

So the equation becomes

2w%5E2+-+3w+%2B+1+=+0

Now we factor the left side:

%282w-1%29%28w-1%29=0

2w-1=0 gives w=1%2F2

w-1=0 gives x=1

But we want x, not w, so since

x+=+w%5E2

For w=1%2F2

x+=+w%5E2+=+%281%2F2%29%5E2+=+1%2F4  

For w=1

x+=+w%5E2+=+1%5E2+=+1  

Edwin