(22⋅4−1)1/2=?(2^2 \cdot 4^{-1})^{1/2} = ?(22⋅
Inside the bracket 22⋅4−1=4⋅14=12^2\cdot 4^{-1}=4\cdot\frac{1}{4}=122⋅4−1=4⋅41=1, and 11/2=11^{1/2}=111/2=1.