Question

Can we write 4.9 square as 5 square - 0.1 square

Answer 1

No brother, you can't ...

because ( 4.9 )^2 = (5-0.1)^2 , which is equal to :

( 5) ^2 + (0.1)^2 - (2*0.1*5) [ as per the indentity , (a - b)^2 = a^2+ b^2-2ab ]