A book's price is doubled and 3 is added. If the resultant is tripled, it becomes 33. What is the price of the book?

Question

I don't know the formula to use and how to solve it

Answer 1

so we double the book's price (2b), and then add three (+3). After that, we multiply again by 3. The final total is 33. That gives us the following:

3(2b + 3) = 33

 

So now we need to find b. Start by dividing both sides by 3:

3(2b + 3) / 3 = 33 / 3

2b + 3 = 11

From here, this looks much like many other algebra problems, doesn't it? All you need to do is subtract 3 from both sides, then divide by 2 to get your final answer.

Answer 2

3(2x + 3) = 33

6x + 9 = 33

6x = 24

x = 4 (the price of the book)