Question

Which set notation correctly expresses the solution set to the equation 31-9x=4

A. {3}

B. (3)

C. {x=3}

D. (x=3)

Answer 1

To solve the equation \( 31 - 9x = 4 \):

1. Subtract 31 from both sides:
\[
-9x = 4 - 31
\]
\[
-9x = -27
\]

2. Divide by -9:
\[
x = \frac{-27}{-9} = 3
\]

The solution to the equation is \( x = 3 \).

Now let's analyze the answer choices given in terms of set notation:

A. \{3\} - This correctly represents the solution as a set containing the number 3.

B. (3) - This is not a standard notation for expressing a solution set.

C. \{x=3\} - This is also not standard; it represents a set containing the statement \( x = 3 \), not the solution itself.

D. (x=3) - This is not a correct representation of a solution set.

The correct answer, expressing the solution set in proper set notation, is:

**A. \{3\}**