11.
\(a,\sqrt{16}\cdot\sqrt{25}+\sqrt{196}:\sqrt{49}\)
\(=4\cdot5+14:7=22\)
\(b,\left(\sqrt{28}-\sqrt{63}+\sqrt{7}\right):\sqrt{7}\\ =\left(2\sqrt{7}-3\sqrt{7}+\sqrt{7}\right):\sqrt{7}\\ =0:\sqrt{7}=0\)
\(c,\sqrt{2,5}\cdot\sqrt{30}\cdot\sqrt{48}=\sqrt{2,5\cdot30\cdot48}=\sqrt{25}\cdot\sqrt{144}=5\cdot12=60\)
\(d,\sqrt{3\dfrac{1}{16}\cdot2\dfrac{14}{25}\cdot2\dfrac{34}{81}}=\sqrt{\dfrac{49}{16}\cdot\dfrac{64}{25}\cdot\dfrac{196}{81}}=\dfrac{7}{4}\cdot\dfrac{8}{5}\cdot\dfrac{14}{9}=\dfrac{196}{45}\)
Bài 11:
a) Ta có: \(\sqrt{16}\cdot\sqrt{25}+\sqrt{196}:\sqrt{49}\)
\(=4\cdot5+14:7\)
=22
b: Ta có: \(\left(\sqrt{28}-\sqrt{63}+\sqrt{7}\right):\sqrt{7}\)
\(=\left(2\sqrt{7}+\sqrt{7}-3\sqrt{7}\right):\sqrt{7}\)
=0
