Remember that factoring allows you to solve equations: can be solved by so that a- b= 0 or a= b and a+ b= 0 or a= -b are solutions.

Ifit were possible to factorwith real coefficients(wecanfactor it as ) then it would be possible to find non-zero a and b so that and of course, that is not true. Since the square of any non-zero number is positive, if a and b are not both 0, then must be positive, not 0.