Algebra: A Combined Approach (4th Edition)

$y_{1}=1 + 2\sqrt{6}$ and $y_{2}=1-2\sqrt{6}$
Given $(y-1)^2=24 \longrightarrow y-1=\pm \sqrt{24}\longrightarrow y-1=\pm 2\sqrt{6} \longrightarrow y=1\pm 2\sqrt{6}$ Therefore the solutions are: $y_{1}=1 + 2\sqrt{6}$ and $y_{2}=1-2\sqrt{6}$