Question

Which of the following equations have the solution of x =3? Choose the THREE correct answers.
A. 2x = 5

B. 3x = 1

C. 5x + 6 = 21

D. 7x - 2 = 19

Answer 1

To determine which equations have the solution \( x = 3 \), we will substitute \( x = 3 \) into each equation and check if the equation holds true.

**A. \( 2x = 5 \)**
Substituting \( x = 3 \):
\[ 2(3) = 5 \to 6 = 5 \] (False)

**B. \( 3x = 1 \)**
Substituting \( x = 3 \):
\[ 3(3) = 1 \to 9 = 1 \] (False)

**C. \( 5x + 6 = 21 \)**
Substituting \( x = 3 \):
\[ 5(3) + 6 = 21 \to 15 + 6 = 21 \to 21 = 21 \] (True)

**D. \( 7x - 2 = 19 \)**
Substituting \( x = 3 \):
\[ 7(3) - 2 = 19 \to 21 - 2 = 19 \to 19 = 19 \] (True)

The equations that have the solution of \( x = 3 \) are:

**C. \( 5x + 6 = 21 \)**
**D. \( 7x - 2 = 19 \)**

Now we need to find one more equation that fits, but from the options given, only C and D are correct. Let's conclude that only two equations have \( x = 3 \) as a solution.
Only options C and D are the correct answers, and no third option is provided.