Four Fours/84

Puzzle

Using exactly $4$ instances of the number $4$, the task is to write an expression for $84$, using whatever arithmetical operations you consider necessary.

Solutions

Solution $1$

$84 = \paren {4! + 4} \times \sqrt {\dfrac 4 {. \dot 4} }$

Solution $2$

$84 = \dfrac {4! + 4! \times .4} {.4}$

Solution $3$

$84 = \sqrt 4 \times 44 - 4$

Also see

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