SOLUTION: we are to solve the following algebraically. I am not sure how to type this out for you but It is a fraction, so there is no division. A) 1/4=3-2x-1/x+2 The work I have do

Algebra ->  Radicals -> SOLUTION: we are to solve the following algebraically. I am not sure how to type this out for you but It is a fraction, so there is no division. A) 1/4=3-2x-1/x+2 The work I have do      Log On


   



Question 129655: we are to solve the following algebraically. I am not sure how to type this out for you but It is a fraction, so there is no division.

A) 1/4=3-2x-1/x+2 The work I have done on it is 1/4=3/1-2x-1/x+2 =
1/4=(3/1)(x+2/x+2)-2x-1/x+2 = 3x+6/x+2-2x-1/x+2 1/4 = x+5/x+2
B)x^3/2=125
c) 3 cuberoot of x-4=2

Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
we are to solve the following algebraically. I am not sure how to type this out for you but It is a fraction, so there is no division.

A) 1%2F4=%283%28x%2B2%29%29%2F%281%28x%2B2%29%29-+%282x-1%29%2F%28x%2B2%29 
   1%2F4=%283x%2B6%29%2F%28x%2B2%29-%282x-1%29%2F%28x%2B2%29
   1%2F4=%28%283x%2B6%29-%282x-1%29%29%2F%28x%2B2%29
   1%2F4=%283x%2B6-2x%2B1%29%2F%28x%2B2%291%2F4=3-%282x-1%29%2F%28x%2B2%29    
   1%2F4=3%2F1-%282x-1%29%2F%28x%2B2%29 
   1%2F4=%28x%2B7%29%2F%28x%2B2%29
  
You almost made it to here, but you missed a sign
by skipping a step, causing you to get a 5 where there 
should be a 7. 

Now enclose both sides in parentheses:

   %281%2F4%29=%28%28x%2B7%29%2F%28x%2B2%29%29

Now multiply both sides by LCD = 4%28x%2B2%29 or %28%284%28x%2B2%29%29%2F1%29

   

Cancel:

   
 
        x%2B2+=+4%28x%2B7%29

x%2B2=4x%2B28

x-4x=28-2

-3x+=+26

x+=+-26%2F3

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

Although the above method is correct, it is
not the normal way to do it.  You begin by
multiplying through by the LCD, not waiting
until later, as you did above. Here is how
it is normally done:

Do the first two steps as you did above:

   1%2F4=3-%282x-1%29%2F%28x%2B2%29    
   1%2F4=3%2F1-%282x-1%29%2F%28x%2B2%29 

Now enclose every term in parentheses:

   %281%2F4%29=%283%2F1%29-%28%282x-1%29%2F%28x%2B2%29%29

Multiply every term on both sides by the 
LCD = 4%28x%2B2%29 or +%28+%284%28x%2B2%29+%29%2F1%29+

   

Cancel:

   

   x%2B2=4%2A%28x%2B2%29%2A3+-+4%2A%282x-1%29
   x%2B2=12%28x%2B2%29+-+4%2A%282x-1%29
   x%2B2=12x%2B24+-+8x%2B4%29
   x%2B2=4x%2B28
   x-4x=28-2
   -3x=26
   x=-26%2F3

   
B)x%5E%283%2F2%29=125

Enclose both sides in parentheses:

   %28x%5E%283%2F2%29%29=%28125%29

Raise both sides to the reciprocal of 3%2F2 power,
which is the 2%2F3 power:

   %28x%5E%283%2F2%29%29%5E%282%2F3%29=%28125%29%5E%282%2F3%29

Multiply exponents on the left, +%283%2F2%29%282%2F3%29+ = 1

Write the right side using the rule A%5E%28B%2FC%29=+%28root%28C%2CA%29%29%5EB+

   x%5E1+=+%28root%283%2C125%29%29%5E2+

Since the cube root of 125 is 5, we have:

   x+=+%285%29%5E2

   x+=+25

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

c) 3%2Aroot%283%2Cx-4%29=2 

Enclose both sides in parentheses:

   %283%2Aroot%283%2Cx-4%29%29=%282%29

Cube both sides:

   %283%2Aroot%283%2Cx-4%29%29%5E3=%282%29%5E3

   %283%5E3%29%28root%283%2Cx-4%29%29%5E3=8

   %2827%29%28root%283%2Cx-4%29%29%5E3=8

When you cube a cube root you take away
the radical:

   %2827%29%28x-4%29=8

   27x-108=8

   27x=8%2B108

   27x+=+116

   x=116%2F27

Edwin