Part A: 0.7(x)
Part B: 8.96/0.7 ---> (You can solve this by yourself)
For getting the answer, you can assume the regular price of the book is x. Then, the sale price would be x-0.3x, which is 0.7x
For part B, the price is 0.7 of the original. Dividing the number by 0.7 gets you the original price