perry has 81 red balls, which she wants to arrange in rows. if the number of balls in each row must be equal to the number of rows, how many balls must there be in a row?
Let there be x the number of rows and y the number of balls in each row.We know that x=y=k and x•y=81 =>k•k=81=>k^2=81=>k=√81=9=>x=9 ; y=9.(there must be 9 balls in a row)
