Mastering the Algebra of Linear Equations: Proving +(-2) = −(−2) = −b ⇒ 1 = −b ⇒ b = −1

Understanding linear equations is fundamental in algebra, and today we break down a clear, step-by-step solution to the equation:

> +(−2) = −(−2) ⇒ 1 = −b ⇒ b = −1

Understanding the Context

This derivation exemplifies how simplifying expressions step-by-step can unlock the value of unknown variables—critical skills for students, teachers, and anyone working in mathematics.


What Does +(−2) = −(−2) Mean?

At first glance, +(−2) might confuse beginners, but it’s simply the additive inverse of 2, which equals −2. Similarly, −(−2) represents the negation of −2, and by the rules of signs, this becomes:

Key Insights

−(−2) = +2

So, the left-hand side simplifies to 2:

> +(−2) = −(−2) ⇒ 2


But now, the equation continues as:

Final Thoughts

> 2 = −b

This is where simplification leads to a key step: recognizing that “−b⇔b with a negative sign shows _b is the negation of 2. Thus,

> −b = 2

⇒ b = −2

Wait—this seems to contradict the earlier claim (⇒ b = −1). Let’s clarify.


Clarifying the Original Equation Step-by-Step

The original statement presented is:

> +(−2) = −(−2) ⇒ 1 = −(b) ⇒ b = −1

Let’s map it carefully, even if it appears inconsistent:

  1. Start with:
     + (−2) = −(−2)
     This is valid because the left side equals −2, the right side equals +2—but wait—there’s a critical sign mismatch here.