Question

show that square of any positive integer is of the form 5m or 5m+1 or 5m-1​

Answer 1

let Abe positive integer be a and b be 5

so a= bq+r and a= 5q+r

so a can be 5q+1,5q+2,5q+3,5q+4,5q

since 5q+2,5q+4are divisible by 2therefore they are even integers

therefore 5q,5q+1,5q+3 are odd positive integer s