1. 8/9 ÷ 4/9 is done by inverting the divisor (4/9) and then multiplying:
(8/9)(9/4) = 8/4 = 2 (answer)
2. 1/3 ÷ 6 is done similarly: (1/3)(1/6) = 1/18 (answer)
3. 4 ÷ 1/5 = 4 * 5 = 20 (answer)
4. 7 1/2 ÷ 1/4 = (15/2)(4/1) = 30 (answer)
Answer:

Step-by-step explanation:
Given

Required
Evaluate when n = 12
Substitute 12 for n in 

Simplify the fraction


Answer:
4x^3-16x^2-28x+40
It will take a while to describe how i got this, but i checked the zeroes are ok.