Evaluate 2 +₆ 4⁻¹ +₆ 3⁻¹

Question:

Let \( +_6 \) be addition modulo 6 on the set \( S = \{0,1,2,3,4,5\} \). Evaluate:

\[ 2 +_6 4^{-1} +_6 3^{-1} \]

Concept:

In addition modulo \(6\), the inverse of \(a\) is:

\[ a^{-1} = 6 – a \]

Solution:

Step 1: Find inverses

  • \(4^{-1} = 6 – 4 = 2\)
  • \(3^{-1} = 6 – 3 = 3\)

Step 2: Substitute

\[ 2 +_6 2 +_6 3 \]

Step 3: Add modulo 6

\[ 2 + 2 + 3 = 7 \equiv 1 \pmod{6} \]

Final Answer:

\[ \boxed{1} \]

Next Question / Full Exercise

Spread the love

Leave a Comment

Your email address will not be published. Required fields are marked *