Answer: a). 11449 b). 39996 e). 996004
Explanation:
107^2
= (100+7)^2
= (100+7)(100+7)
= 10000 + 700 + 700+ 49
= 10000 + 1400 + 49
= 11449
198 x 202
= (200-2)(200+2)
= 40000 - 4
= 39996
998^2
= (1000-2)(1000-2)
= 1000000 - 2000 - 2000 + 4
= 1000000 - 4000 + 4
= 996000 + 4
= 996004
