1.      Find the values using appropriate identities.

a.      ^{[6 1/2  ] 2    -   [5 1/2  ] 2}            

b.     50.3²  

c.      105²

d.     ^{[30 1/2  ]  2}  

e.     10.2²

f.       198²

g.     197  ×  298

h.     168² - 162²

i.       26.5   ×  23.5

j.       224  ×  176    -   226  × 176

k.     (2X -  3Y) × (3X -  2Y)

l.       (2X +  3Y)²

1.     Take nine numbers forming a square in a calendar and mark the four numbers at the corners.   add the squares of diagonal pairs and find the difference of the sums. Explain the general principle using algebra.
2.   Take any four consecutive natural number find difference of the product of first and last and middle two. Explain general principle using algebra
3.     Fill in the blank column

x	y	z	X+ y	XZ	YZ	(X+Y)z	XZ + YZ
1	-1	3
-1	1	-2
3	-2	1
-2	3	-1

          Write the general principle of the above

      4. .  Find y  when x =    - 1/4      , - 1/2  ,  2     

a.      Y  =   1/(x-1)   +   1/(x+1)  

b.       Y  =  (x+2)/(x-1)

 c.      Y= 2x² + 3x  -  1

    d.      Y =  X²  +  2X  - 1

5.     If x = 2 ,y = -1   find z

                   Z  =  X²  +  2X Y – Y²