Solve it by reversing what is done to the number. You don't need an equation to do that.
17 is 7 less than ...
so adding 7 to 17, making 24, will give you ... one-fourth of the number. If 24 is one-fouth of the number, multiplying 24 by 4 will give you the number. Doing that tells you the number is 96.
_____
You can do the same solution process using an equation.
(1/4)n - 7 = 17 . . . . . 7 less than 1/4 of a number is 17
(1/4)n = 24 . . . . . . . add 7
n = 4·24 = 96 . . . . multiply by 4
The number is 96.