Simplify: 500 x 500- 200 x 200  Choose the correct choice from the following answers
A) 761200
B) 761400
C) 761800
D) 210000
E) None of them
(500)^2 - (200)^2 = (500 + 200) (500 - 200) = 700 x 300 = 210000.   Answer is 210000.
<result>D</result>
Simplify: 500 x 500- 200 x 200