To solve for the width (w) of a rectangle using the formula $P = 2l + 2w$, here are the correct steps. I'll break them down and specify which step should come first:

Step-by-Step Approach:

1. First Step:

   • Isolate the terms involving w.
   • Begin by subtracting $2l$ from both sides of the equation: $P - 2l = 2w$ This isolates the term containing w on one side of the equation.

2. Second Step:

   • Solve for w by dividing both sides by 2: $w = \frac{P - 2l}{2}$ This completes the process of solving for w.

So the correct first step is:

• Subtract $2l$ from both sides.

Would you like more details or do you have any other questions?

Here are 5 related questions:

1. How do you isolate a variable in an equation?
2. What other geometric shapes have similar perimeter formulas?
3. If the perimeter is given, how can you calculate the length, $l$, after finding $w$?
4. Can the perimeter formula be used for non-rectangular shapes?
5. What happens if the perimeter formula involves unknown variables for both $l$ and $w$?

Tip: When solving equations, always focus on isolating the variable of interest by undoing operations step-by-step.