Could someone give me a method to this question?:
Rewrite 9991 as the difference of two squares. Use your answer to find the prime factors of 9991.
Than could someone give me methods to work out any of these annoying square number questions?
Could someone give me a method to this question?:
Rewrite 9991 as the difference of two squares. Use your answer to find the prime factors of 9991.
Than could someone give me methods to work out any of these annoying square number questions?
anothe method :
let $\displaystyle a^2-b^2=9991$, then $\displaystyle (a-b)(a+b)=9991$.
one of the solution (i think it is a trivial solution) is $\displaystyle a-b = 1$ and $\displaystyle a+b=9991$.
solve it, we get $\displaystyle a=4996$, and $\displaystyle b=4995$