The answer to this question is -6.
To solve this problem, we need to understand certain properties about exponents. To begin, let's remember that when we raise a number, the base, in this case y, to a certain power that is then raised to another power, we multiply these two exponents together when evaluating. Another important concept that is vital to understanding this problem is that negative exponents are positive exponents in the denominator of fractions. For example, y^-4 = 1/y^4.
Using this knowledge, we know that b * 4 must equal 24 (because raising a power to another power implies multiplication). Therefore, we know that the magnitude of the variable b must be six. However, we must also recognize that y^24 is in the denominator of the answer, which means that one of the exponents of the variable y must be negative. Since the exponent 4 is not negative, the exponent of b, or 6, must be.
Therefore, your answer is -6.
If you do not understand my explanation, feel free to ask me any clarifying questions.
Hope this helps!