Second grade mathematics 108 page 9 Question 9 ah, please quickly give the answer, a good supplementary score

Second grade mathematics 108 page 9 Question 9 ah, please quickly give the answer, a good supplementary score

According to the account records of a store, one day, 39 toothbrushes and 21 boxes of toothpaste were sold, and the income was 396 yuan. The other day, 52 toothbrushes and 28 boxes of toothpaste were sold at the same price, and the income was 518 yuan

1,2,3,4,5,7,9,11,15,21,27,29,39,41,46,51,46 which prime numbers and which combined numbers?

Prime number: 2 3 5 7 11 29 41
Total: 4915 21 27 39 46 51 46

The law and m value of sequence 2, 3, 5, 7, 9, m, 17, 19, 23

M=12
2*2-1=3
3*2-1=5
5*2-1=7
General formula
[A(N)]*2-1=[A(N+1)]