Iam thinking of a number such that 6 less than the product of 7 and this number is 85 which number is she thinking of

6 less than the product of 7 and this number is 85.
6 less than (the product of (7 and this number)) is 85.

6 less than (the product of 7 and x) = 85
6 less than (7 * x) = 85
(7 * x) - 6 = 85

Now you solve! Make sure that whatever you do to one side you also do to the other:
7x - 6 = 85
7x - 6 + 6 = 85 + 6
7x = 91
7x /7 = 91 /7
x = 13

Hope this helps! :)