If 3 + x = 10, what is x?

If 3 + x = 10, what is x?

• A. 6
• B. 7
• C. 8
• D. 9

Answer: (B)

To find the value of x in the equation 3 + x = 10, we start by isolating x. This can be done by subtracting 3 from both sides of the equation. When we execute this step, our equation becomes: x = 10 - 3. Now we perform the subtraction on the right side: x = 7. Thus, the correct answer is that x equals 7. This solution illustrates the fundamental concept of balancing equations—what you do to one side must also be done to the other. This is a key principle in solving for unknowns in algebra, which is foundational for mathematical understanding in early education.

To find the value of x in the equation 3 + x = 10, we start by isolating x. This can be done by subtracting 3 from both sides of the equation.

When we execute this step, our equation becomes:

x = 10 - 3.

Now we perform the subtraction on the right side:

x = 7.

Thus, the correct answer is that x equals 7. This solution illustrates the fundamental concept of balancing equations—what you do to one side must also be done to the other. This is a key principle in solving for unknowns in algebra, which is foundational for mathematical understanding in early education.