b-9 7
---- / ---
b b
Since there is one b at the top and one b at the bottom those cancel out, and we are left with one b at the bottom
-9 7
--- / ---
b 1
When we divide fractions, we have to KCF (Keep, change, flip) Meaning keep the first fraction, change the division to multiplication, and flip the second fraction.
-9 7
--- x ---
b 1
Now we can multiply the numerator x numerator, then the denominator x denominator. -9 x 7 = -63, and b x 1 = b
So the final answer is -63/b