Evaluate [475X475 + 125X125] = ?

Ans :
[(475) pow 2 + (125) pow 2]

We know that

a pow 2 + b pow 2 =1/2[(a+b) pow 2 + (a-b) pow 2]

So We can write expression as :

1/2 [(600) pow 2 + (350) pow 2]= 1/2[360000+122500]
1/2 X 482500=241250