Nội dung bài giảng
Bài 11. Tính:
a) \(\sqrt{16}.\sqrt{25} + \sqrt{196}:\sqrt{49}\);
b) \(36:\sqrt{2.3^2.18}-\sqrt{169}\);
c) \(\sqrt{\sqrt{81}}\);
d) \( \sqrt{3^{2}+4^{2}}\).
Hướng dẫn giải:
a) \(\sqrt{16}.\sqrt{25} + \sqrt{196}:\sqrt{49}=4.5+\frac{14}{7}=22\)
b) \(36:\sqrt{2.3^2.18}-\sqrt{169}\)
\(=\frac{36}{\sqrt{2.3^2.3^2.2}}-\sqrt{13}\)
\(=\frac{36}{18}-13=-11\)
c) \(\sqrt{\sqrt{81}}\)\(\sqrt{\sqrt{9^2}}=\sqrt{|9|}=\sqrt{9}=3\)
d) \(\sqrt{3^{2}+4^{2}}=\sqrt{16+9}=\sqrt{25}=5\)