INTRODUCTORY EXERCISES - Symbol Manipulation

(2) Factor. Simplify further where appropriate. For (d) and (e),
 indicate what values of the variable make the expression undefined.

 
 (a) 42t2 - 6yt - 96xt

 (b) x - 2x2

 (c) (5a + b)(a - b) - 11b(a - b)

 (d) y2 + y
     -------
      y + 1

 (e) 4x2 + 8x
     --------
        2x3 

 
 Take out common factors in each question.  Then simplify (may involve 
 cancelling common factors in the case of fractions).