In order to realize the balanced development of regional education, our city plans to transform all the weak schools of A and B in a county. According to the budget, the reconstruction needs a total of15.75 million yuan. Solution: (1) The funds required for the establishment and renovation of Class A schools and Class B schools are A million yuan and B million yuan respectively.

According to the meaning of the question:

Solution:

That is, the funds needed to transform a class A school and a class B school are 600,000 yuan and 850,000 yuan respectively;

(2) There are M, N, A and B schools in this county.

Then 60m+85n= 1575,

solve

* There are no more than five Class A schools,

∴

∴n≥ 15，

That is, there are at least 15 Class B schools;

(3) If X Class A schools are renovated this year, the number of Class B schools will be (6-x), and the renovation funds invested by the state will be: 60- 10=50 (ten thousand yuan) for Class A schools and 85- 15=70 (ten thousand yuan) for Class B schools.

According to the meaning of the question:

Solution: 1≤x≤4,

∵x takes integer,

The value of x is 1, 2, 3, 4,

That is, there are four transformation schemes.