Question

URGENT!!!! AM NEVOIE VA ROG

Answer 1

Explicație pas cu pas:

$\sqrt{2019 \cdot 2020 + \sqrt{2019 \cdot 2020 + \sqrt{\underbrace{2019 \cdot 2020}_{ < \ 2020 \cdot 2020}} }} <$

$< \sqrt{2019 \cdot 2020 + \sqrt{2019 \cdot 2020 + \sqrt{2020 \cdot 2020} }}$

$= \sqrt{2019 \cdot 2020 + \sqrt{2019 \cdot 2020 + 2020 }}$

$= \sqrt{2019 \cdot 2020 + \sqrt{2020 \cdot (2019 + 1)}}$

$= \sqrt{2019 \cdot 2020 + \sqrt{2020 \cdot 2020}}$

$= \sqrt{2019 \cdot 2020 + 2020} = \sqrt{2020 \cdot (2019 + 1)}$

$= \sqrt{2020 \cdot 2020} = 2020$

q.e.d.