Question

Фастом ответ , спасибо

Answer 1

Ответ:

1. [0;+∞)

2. [3;+∞)

Объяснение:

$1.\left \{ {{x\geq 0} \atop {x+7}\geq 0} \right.=>\left \{ {{x\geq 0} \atop {x\geq -7}} \right.=>x\geq 0$

x∈[0;+∞)

$2.\left \{ {{x\geq 0} \atop {x-3\geq 0}} \right.=>\left \{ {{x\geq 0} \atop {x\geq 3}} \right.=>x\geq 3$

x∈[3;+∞)

Answer 2

$1) \ \sqrt{x} +\sqrt{x+7} \\\\\\\displaystyle\left \{ {{x\geq 0} \atop {x+7\geq 0} \right. \\\\\\\displaystyle\left \{ {{x\geq 0} \atop {x\geq -7}} \right. \ \Rightarrow \ x\geq 0\\\\\\Otvet:\boxed{x\in\Big[0 \ ; \ +\infty\Big)}$

$1) \ \sqrt{x} +\sqrt{x-3} \\\\\\\displaystyle\left \{ {{x\geq 0} \atop {x-3\geq 0} \right. \\\\\\\displaystyle\left \{ {{x\geq 0} \atop {x\geq 3}} \right. \ \Rightarrow \ x\geq 3\\\\\\Otvet:\boxed{x\in\Big[3 \ ; \ +\infty\Big)}$