Baking powder is primarily used as a leavening agent in baked goods and products. It is a combination of cornstarch, cream of tartar and baking soda. The main observation that suggests that it is a mixture of substances is that fact that it produces a gas which facilitates the rising of the baked goods.
Answer: The answer is the first one and the last one.
Explanation: If an account cost $1 and each song is 1.5x. It has to be less than or equal to 25. So it would be $1 for (the account plus) 1.5x for (how many songs he buys) is less than or equal to 25 (the ammount on the gift card).
The answer would be Cauterization