Evaluating an Expression with One Variable

A mathematical expression can have a variable as part of the expression. If x=3, the expression 7x + 4 becomes 7 * 3 + 4 which is equal to 21 + 4 or 25. To evaluate an expression with a variable, simply substitute the value of the variable into the expression and simplify.

          an illustrative example is presented below:

          Exercise:

          Evaluate the following expressions given the values of the variable:

           1.   (3x + 2) - (2x - 3) ;  x = 6

           2.  x (x - 2)                 ;  x = 4 

           3.  x + 2x + 3x + 4x + ... + 10x ; x = 2

        

Challenge : 

( x + (x/2) + (x/3) + (x/4) + (x/5) + ... + (x / 20)) / x ; x = 1/2

note: for the challenge activity, merit point to those who will submit a correct solution on or   

before 8:00 AM on March 09, 2012.