Okay, the image is a little tough to see, but I believe it looks something like this:
(5² -10 / 17 - 3 * 4) -1
The first step [remember PEMDAS] is parentheses
Next comes Exponents:
(25 - 10 / 17 - 3 * 4) -1
Then Multiplication:
(25 - 10 / 17 - 12) - 1
Then Division [which we can't do yet since it isn't fully simplified], so we skip to Addition... nothing again, then subtraction.
(15 / 5) - 1
Then we can divide:
(3) - 1
Then subtract!
2
The answer to your problem is 2.
Hope that helps!