Four Fours/9

Puzzle

Using exactly $4$ instances of the number $4$, the task is to write an expression for $9$, using whatever arithmetical operations you consider necessary.

Solutions

Solution $1$

$9 = 4 + 4 + \dfrac 4 4$

Solution $2$

$9 = \sqrt {\dfrac 4 {.\dot 4} } \times \sqrt {\dfrac 4 {.\dot 4} }$

Solution $3$

$9 = \paren {\sqrt {\dfrac 4 {.\dot 4} } }^{\tfrac 4 {\sqrt 4} }$

Also see

Previous  ... Next