Linear Algebra

A system of linear equations $A x = b$ with $m$ equations and $n$ unknowns has a unique solution if and only if:

Options:

• (A) $\text{rank}(A) = \text{rank}([A|b]) = n$
• (B) $\text{rank}(A) = \text{rank}([A|b]) < n$
• (C) $\text{rank}(A) < \text{rank}([A|b])$
• (D) $m > n$