The numerator n- 13 has a common divisor with the denominator 5n+6.
Find the minimum value of positive integer n, that is, what is the value of n when the numerator denominator takes the greatest common divisor,
From the original score, you get
5n+6n- 13，
= 5(n- 13)+7 1n- 13，
=5+
7 1n- 13，
The common divisor of ∴7 1 and n- 13 is greater than 1,
71is a prime number,
When ∴n- 13=7 1, n is the smallest.
That is, n = 84. Go to this website and see/math/ques/detail/d1ed5f31-33fb-4df7-a7fd-eeff323ee66a.