SEAMO 2027 - Paper D - SET 08 - Self-study Question 20

For real $x$, let $[x]$ be the largest integer not exceeding $x$, and let $\{x\}=x-[x]$. Let $a,b$ be real numbers with $b$ nonzero and $a=b[a/b]-b\{a/b\}$. Which statement is incorrect?

Notation clarification: the source omits braces in its fractional-part definition. Here {x}=x−[x]. The minus sign in the given equation is retained exactly.