Question

giúp mình câu d ạ

Answer 1

\(\sqrt{98}-\sqrt{72}+0,5\sqrt{8}=7\sqrt{2}-6\sqrt{2}+0,5.2\sqrt{2}=\sqrt{2}+\sqrt{2}=2\sqrt{2}\)

Answer 2

d, \(\sqrt{16b}+2\sqrt{40b}-3\sqrt{90b}\)

\(=4\sqrt{b}+4\sqrt{10b}-9\sqrt{10b}\)

\(=4\sqrt{b}+-5\sqrt{10b}\)

Answer 3

\(\sqrt{16b}+2\sqrt{40b}-3\sqrt{90b}\)

\(=4\sqrt{b}+4\sqrt{10}b-9\sqrt{10}b\)

\(=\left(4-5\sqrt{10}\right)b\)