Answer: 
Step-by-step explanation:
10 pens - 2 pens = 8 pens
Write 8 of 10 as a fraction.
You get
, right?
Now, simplify 8/10.
You get 4/5.
I'm assuming the problem is nine to the third power divided by nine to the ninth power, so the answer would be 0.000001882. Fraction form would be 1/531441.
Sorry about the first answer, I read the problem wrong.
The answer is nine: 17 minus 8 is 9