\begin{gathered}y = \sqrt{2x + 4} \\ 2x + 4 \geqslant 0 \\ 2x \geqslant - 4 \\ x \geqslant - 2 [ - 2;+\infty)\end{gathered}
y=
2x+4
2x+4⩾0
2x⩾−4
x⩾−2[−2;+∞)
