how far have you gone, show what you've tried please
Sorry didn't explain clearly
I have 11 symbols (6 letters ABCDEF and +-*/^)
in each arrangement i use the 11 symbols but the first and second symbol must begin with a letter
so i try this
for 9 symbols i have 9! and for the for the first and second symbol 6*5
so 6*5 * 9!