2,3,5,17, (), 56 regular filling

2,3,5,17, (), 56 regular filling

thirty-nine

What is the difference between the largest square in 25, 56, 17 and the product of the remaining two numbers?

56^2-25*17 = 2711

(68 divided by 56) if the quotient is a single digit, what is the maximum number that can be filled in the box?

1 to 4

When () is filled in (), the quotient is one digit; when () is filled in (), the quotient is two digit

When (1-5) is filled in (15-56), the quotient is one digit; when (6-9) is filled in (6-9), the quotient is two digit