Let the number be x

The other tutor's solution is incorrect because he did the no-no
of dividing an equation through by the variable x.  When you do that
you lose a solution.  He lost the solution 0. His no-no was as bad
if not worse than your misspelling "grateful".  J


x squared equals x times four









Use the zero factor principle:

Setting the first factor  equal 0 gives



Setting the second factor  equal to 0 gives:




So the number could be 0 or 4.

Edwin