Question 207728
If you FOIL out {{{(n-1)(n+1)}}}, you will get: {{{(n-1)(n+1)=n*n+n*1-1*n-1*1=n^2+n-n-1=n^2-1}}}



So {{{(n-1)(n+1)=n^2-1}}} is true for ALL values of 'n'



This means that "The product of a number (n-1) and number (n+1) is always equal to n^2-1" is ALWAYS true. So once again, we cannot find any counter examples because there are none in this case.