Jonny is solving this equation for n: 8+3n=20. His first step is to subtract 8 from both sides of the equation. Why?

8 is the first term in the equation, He needs to follow the order of operations, 8 is attached to 3n by subtraction, He needs to reverse the order of operations

1 answer

Jonny's first step in solving the equation \( 8 + 3n = 20 \) is to subtract 8 from both sides of the equation in order to isolate the term with \( n \). This step is necessary to simplify the equation.

Here's the reasoning:

When dealing with equations, the goal is to isolate the variable (in this case, \( n \)). By subtracting 8 from both sides, Jonny is effectively undoing the addition of 8. This follows the basic principle of equations: whatever operation you perform on one side must also be performed on the other side to maintain balance.

So, to clarify the correct explanation:

  • He needs to reverse the operation: Since the equation has \( 8 \) being added to \( 3n \), to isolate \( 3n \), he subtracts \( 8 \) from both sides. This will give him \( 3n = 20 - 8 \), simplifying to \( 3n = 12 \).

This is not just about "order of operations"; it's about maintaining equality and solving for the variable.