Four Fours/51/Solutions/3

Puzzle: Four Fours: $51$

Using exactly $4$ instances of the number $4$, the task is to write an expression for $51$, using whatever arithmetical operations you consider necessary.

Solution

$51 = \dfrac {4!} {. \dot 4} - \sqrt {\dfrac 4 {. \dot 4} }$

Sources

• 1964: L.H. Clarke: Fun with Figures ... (previous) ... (next): Solutions: $(46)$