a+b÷c=5

b+a÷c=7

Add these two types together and you will get

(a+b)+(a+b)÷c= 12

In the number 1-9, the sum of the two numbers can only be divisible by 2 and 3, so c can only be equal to 2 or 3.

When c=2, a=6 and b = 2;

When c=3, a=6 and b = 3.

So (a+b)÷c=(6+2)÷2=8÷2=4,

Or (a+b) ÷ c = (6+3) ÷ 3 = 9 ÷ 3 = 3.

So the correct result is 3 or 4.

So the answer is: 3 or 4.