Question

Which of the following could be the first step in solving the equation 5x = 21?

A) 5* = 5/21
B) 5.5* = 5•21
C) log 5* = 21
D) log 5x = log 21

Answer 1

The first step in solving the equation 5x = 21 is to divide both sides by 5 to isolate the variable x, which is not listed in the presented options A to D.

Step-by-step explanation:

The first step in solving the equation 5x = 21 is to isolate the variable x. We do this by performing operations that will leave x by itself on one side of the equation. The most straightforward method is to divide both sides of the equation by 5, the coefficient of x. This yields:

x = 21/5

Therefore, the correct first step in solving this equation from the provided options is none of the above since the division by 5 is the required operation to isolate x, which is not present in the options A to D. Options involving multiplication, logarithms, or exponentiation are not appropriate for this linear equation.