must be a positive integer, which means
must be a
positive integer, so z must have factor 31.
must be a positive integer, which means
must be a
positive integer, so z must have factor 20.
So the smallest integer that meets those two conditions is 31×20 or 620
Now let's see if 620 meets the third condition
or
must be a positive integer, and since
= 4, 620 meets all 3 requirements so we know that 620 is the answer.
Edwin