To rearrange the formula \( y = mx + b \) using \( x \) as the quantity of interest, the first step would be to subtract \( b \) from both sides of the equation.
This is because you want to isolate the term containing \( x \). Here’s how the rearrangement looks:
- Start with: \( y = mx + b \)
- Subtract \( b \) from both sides: \( y - b = mx \)
This allows you to eventually solve for \( x \).