Hello,
This is the first of the many posts to come. I am weaker especially when it comes to math. I got the questions from a friends study material; it comes with an answer explanation which I don't seems to grasp!
Question>When a number is divided by 4 the remainder is 3. What will be the remainder when the square of the number is divided by 4.
Answer> The number will be given by 4n-1. The square of this number is 16n^2-8n+1. The remainder when this number is divided by 4 is 1.
What I have tried> Number = Quo*4 + 3......(eq1)
Therefore, Number^2 = (Quo*4 + 3)^2
= 16*Quo^2+24*Quo+9...............(eq2)
Divide this eq2 by 4 we get quotient = 4Quo^2+6*Quo+2 with a remainder of 1.
I believe I have done this correctly but I still want to know whats with the author's explanation. Thank you.