Sunday, December 23, 2012

How Do We Add And Subtract Rational Expressions ?

To add and subtract rational expression, you have to first find a common denominator.

                                                    X-1                X-5        <------ Numerator
                                                  X +6                X+6       <------ Denominator
Lets take :

              u-v               6u -3v
              8v       +          8v 
 The first step in solving this is finding a common denominator. Since this rational expression already is in a common denominator, you don't have to worry about it.

Next you add or subtract the terms, according to what the question ask you. In this case, You add by adding like terms.

          So .....                  u + 6u = 7u   and  -1v-3v = -4v 
                Together the numerator is  7u-4v
                               the denominator is 8v.


NOW TRY THIS : 

                     7p+9z     -     3p+8z
                         9g                 9g


Sunday, December 16, 2012

How Do We Solve Fractional Exponent Equations ?

To solve fractional rational exponents you have to get the variable and exponent alone before first.

 Let's use :  x^4/3 - 6 = 10 .

The first step is to add 6 to both sides to get x^4/3 by itself .
        The equation now looks like : x^4/3 = 16
The next step is to find the reciprocal of the exponent ( 4/3 ) and multiply it to both sides. This gets x by its self.

       Visual :  (x^4/3) (3/4) = 16 (3/4)
                          x = 16 ^ (3/4)
Next you have break up the exponent. You do this by putting 16 ^ (1/4) first. Then squaring that by 3.

           Visual :                               16^ (1/4) = 2.
                                            2^3 = 8 
                                 Your final answer is 8 . 

Now Try It Yourself :
                                        8^(2/3)

* Remember : (1/2) = square roots 
                        (1/3) - cubed root 
                                           
                   

Sunday, December 9, 2012

How Do We Solve Radical Equations ?

Lets use the example :
The first step in solving radical equations is making sure the radical is by itself.

Let's take √x-7 + 5 = 6 , you would have to subtract 5 from each side to get the radical by itself. 
The next step is to square each side of the equation. Do not square terms. 

   Here is an example : 

               CORECT√x-7^2 =1^2
        
                              x-7 =1
The next step is to solve the equation by solving for X. You can do that by getting X alone. In this case it would look like : 

                                     x-7 =  1
                           +7    +7
                              x = 8
The last and final step is to plug the value of X back into the equation to see if it works.


                           8-7 + 5 = 6 ----------> 8-7 is 1

                   √1+ 5  = 6  -----> The square root of 1 is 1.

                           6 = 6  ----------> 1+5 =6

                    The solution X = 8 is true . 



Now try it yourself  :


                             √x-3 = 5

Sunday, December 2, 2012

How Do We Factor By Grouping ?

To factor by grouping, you have to use 5 easy and simple steps.
     Let's use the polynomial : 8x^2-10x-3 
The first step is to find the Master Product. The master product is multiplying the first number by the last number. So in this case you would multiply 8 by -3 and get -24.
The next step if to find what multiplies to give you -24 and adds together to give you -10.
                                    The two numbers become -12 and 2.
Next you replace the -10x with the two new factors you found ( -12 and 2 )
              Your polynomial should now look like this : 8x^2-12x+2x-3
 Now its time to group the the terms in two pairs. Group the first two terms and the last two terms
       You have to factor each pair by finding the greatest common factor.
           So you can pull out 4x from 8x^2 -12 . The first two terms now look like :
                                                 4x(2x-3) 
         You can pull out 1 from 2x -3 because there's nothing else that goes into both 2 and 3.
  Both terms together now looks like this :  4x(2x-3) + 1(2x-3)
      The final and last step is to factor out the shared binomial, which is (2x-3) and combine the term in front of the parenthesis.
                       Your final answer is (4x+1) (2x-3) .

Now try it is your self  :

                                              6x^2 + 19x + 10