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Question Number 155164 by mnjuly1970 last updated on 26/Sep/21
   solve..           ⌊ (( x)/(2+ (√x))) ⌋ = 3        ( x∈ Z )
$$\:\:\:{solve}.. \\ $$$$\:\:\:\:\:\:\:\:\:\lfloor\:\frac{\:{x}}{\mathrm{2}+\:\sqrt{{x}}}\:\rfloor\:=\:\mathrm{3}\:\:\:\:\:\:\:\:\left(\:{x}\in\:\mathbb{Z}\:\right) \\ $$$$ \\ $$
Answered by MJS_new last updated on 26/Sep/21
(x/(2+(√x)))=3 ⇒ x≈19.11  (x/(2+(√x)))=4 ⇒ x≈29.85  (x/(2+(√x))) strictly increasing  ⇒ answer is 20≤x≤29
$$\frac{{x}}{\mathrm{2}+\sqrt{{x}}}=\mathrm{3}\:\Rightarrow\:{x}\approx\mathrm{19}.\mathrm{11} \\ $$$$\frac{{x}}{\mathrm{2}+\sqrt{{x}}}=\mathrm{4}\:\Rightarrow\:{x}\approx\mathrm{29}.\mathrm{85} \\ $$$$\frac{{x}}{\mathrm{2}+\sqrt{{x}}}\:\mathrm{strictly}\:\mathrm{increasing} \\ $$$$\Rightarrow\:\mathrm{answer}\:\mathrm{is}\:\mathrm{20}\leqslant{x}\leqslant\mathrm{29} \\ $$
Commented by mnjuly1970 last updated on 26/Sep/21
bravo  ..perfect..
$${bravo}\:\:..{perfect}.. \\ $$

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