Question

1 Tính

a, \(\sqrt{0,49.169.25}\)

b,\(\dfrac{\sqrt{63}}{\sqrt{112}}\)

c, \(\sqrt{\dfrac{27}{17}}.\sqrt{11.\dfrac{5}{17}}\)

d,\(\sqrt{\left(-5\right)^2.16.225}\)

e,\(\dfrac{\sqrt{2,5}}{\sqrt{1,6}}\)

Answer 1

1)

a) \(\sqrt{0,49.169.25}=\sqrt{0,49}.\sqrt{169}.\sqrt{25}=0,7.13.5=45,5\)

b) \(\dfrac{\sqrt{63}}{\sqrt{112}}=\sqrt{\dfrac{63}{112}}=\sqrt{\dfrac{9}{16}}=\dfrac{\sqrt{9}}{\sqrt{16}}=\dfrac{3}{4}\)

c) \(\sqrt{\dfrac{27}{17}}.\sqrt{11.\dfrac{5}{17}}=\sqrt{\dfrac{27}{17}.11.\dfrac{5}{17}}=\sqrt{\dfrac{1485}{17^2}}=\dfrac{\sqrt{1485}}{\sqrt{17^2}}=\dfrac{\sqrt{9.165}}{17}=\dfrac{\sqrt{9}.\sqrt{165}}{17}=\dfrac{3\sqrt{165}}{17}\)

d) \(\sqrt{\left(-5\right)^2.16.225}=\sqrt{\left(-5\right)^2}.\sqrt{16}.\sqrt{225}=\left|-5\right|.4.15=5.60=300\)

e) \(\dfrac{\sqrt{2,5}}{\sqrt{1,6}}=\sqrt{\dfrac{2,5}{1,6}}=\sqrt{\dfrac{25}{16}}=\dfrac{\sqrt{25}}{\sqrt{16}}=\dfrac{5}{4}\)