On the set Q of all rational numbers if a binary operation * is defined by a∗b=ab/5, prove that * is associative on Q.
Associativity Proof 📺 Watch Video Explanation: Prove that the operation is associative Given: \( a * b = \frac{ab}{5}, \quad a,b \in \mathbb{Q} \) Proof: LHS: \( (a*b)*c = \left(\frac{ab}{5}\right)*c \) \( = \frac{\frac{ab}{5} \cdot c}{5} = \frac{abc}{25} \) RHS: \( a*(b*c) = a*\left(\frac{bc}{5}\right) \) \( = \frac{a \cdot \frac{bc}{5}}{5} = \frac{abc}{25} \) Thus: \( […]