\(\displaystyle \lim_{x\rightarrow ∞} \sqrt{\frac{16x}{4x+9}}\\ =\displaystyle \lim_{x\rightarrow ∞} \sqrt{\frac{16x\div x}{(4x+9)\div x}}\\ =\displaystyle \lim_{x\rightarrow ∞} \sqrt{\frac{16}{4+\frac{9}{x}}}\\ = \sqrt{\frac{16}{4+0}}\\ =\sqrt4\\ =2 \)
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