Question

which of the following could be the first step in solving the equation below?5^x=21a. 1/5×5^x=1/5×21b. log5^x=log21c. log5^x=21d. sqrt[5]{ {5}^{x} } = sqrt[5]{21}

Answer 1

`\log _{}5^x\text{ = log21}`

Step-by-step explanation

We want to find the very first step in solving the problem below:

`5^x\text{ = 21}`

If we wanted to jump steps, we could just state that the equation would become:

`\log _521\text{ = x}`

But that would be jumping a lot of steps and it is not among the options.

So, the very first step in solving this problem is to find the logarithm of both sides.

That is:

`\log 5^x\text{ = log21}`

That is the answer. (Option B)