To isolate x in the equation 3x = 18, which operation should be performed?

To isolate x in the equation 3x = 18, which operation should be performed?

• A. Add 3
• B. Subtract 3
• C. Multiply by 3
• D. Divide by 3

Answer: (D)

To isolate x in the equation 3x = 18, the goal is to find the value of x. In this equation, x is being multiplied by 3. To reverse this operation and solve for x, you need to use the opposite mathematical operation, which in this case is division. Dividing both sides of the equation by 3 allows you to eliminate the coefficient of x. When you divide 3x by 3, it simplifies to x, and when you divide 18 by 3, you get 6. This leads to the solution x = 6. Using division here effectively isolates x, allowing you to solve the equation correctly. The other operations listed do not help isolate x because adding or subtracting 3 would not counteract the multiplication of x by 3, and multiplying by 3 would only increase the value instead of solving for x. Thus, dividing by 3 is the appropriate step to take to isolate x in this equation.

To isolate x in the equation 3x = 18, the goal is to find the value of x. In this equation, x is being multiplied by 3. To reverse this operation and solve for x, you need to use the opposite mathematical operation, which in this case is division.

Dividing both sides of the equation by 3 allows you to eliminate the coefficient of x. When you divide 3x by 3, it simplifies to x, and when you divide 18 by 3, you get 6. This leads to the solution x = 6.

Using division here effectively isolates x, allowing you to solve the equation correctly. The other operations listed do not help isolate x because adding or subtracting 3 would not counteract the multiplication of x by 3, and multiplying by 3 would only increase the value instead of solving for x. Thus, dividing by 3 is the appropriate step to take to isolate x in this equation.