Example 

Find the values of the given expressions. Also given that a = 2, b = 3, c = 1, and x = 2.

1. 8a + 5bc

         =       8.2 + 5.3.1

         =       16 + 15

         =       31

1. 9a + c

         =       9.2 + 1

         =       18 + 1

         =       19

1. x³

         =       2³

         =       2.2.2

         =       8

Now, what would be the value of 8abc, if one of the quantities a, b or c is zero. It will be zero and this is irrespective of other values. A factor which has its value as zero is called zero factor. Remember that every power of zero is zero.

Now is it that we only have quantities of the form 8ab or x³. No, we often come across quantities like     or      In mathematics, the    sign is referred to as a radical sign and at this point let us define what square root is. The square root of any quantity is that value whose square is equal to the given expression. That is,    = 2. If we square two we get four which is the required quantity under the radical sign. Similar to square root we have cube root     , the fourth root      and the fifth root     , etc........ roots. Only that we have to multiply the given quantity the required number of times to get the quantity under the radical sign. Now we look at a couple of examples as how to solve problems having the radical sign.