Bài 1:Tính a)$$\sqrt{9}$$ + $$\sqrt{81}$$ + $$\sqrt{16}$$ b) $$\sqrt{49}$$ + $$\sqrt{25}$$ + $$\sqrt{121}$$ Bài 2 :Tính hợp lý ($$\frac{\sqrt{25}} {11}$$ ) .$$\frac{\sqrt{49}} {15}$$ . ($$\frac{\sqrt{121}} {-5}$$) .$$\frac{1}{7}$$ (-$$\frac{1} {\sqrt{36}}$$ ).( $$\frac{\sqrt{225}} {19}$$ ).$$\frac{38}{45}$$