Question

Rút gọn:

2) \(\sqrt{98}-\sqrt{72}+0,5\sqrt{8}\)

3) \(\sqrt{9a}-\sqrt{16a}+\sqrt{49a}\) với a \(\ge\) 0

4) \(\sqrt{16b}+2\sqrt{40b}-3\sqrt{90b}\) với b \(\ge\) 0

Answer 1

2) \(\sqrt{98}-\sqrt{72}+0,5\sqrt{8}\)

\(=7\sqrt{2}-6\sqrt{2}+\sqrt{2}\)

\(=\left(7-6+1\right)\sqrt{2}\)

\(=2\sqrt{2}\)

3) \(\sqrt{9a}-\sqrt{16a}+\sqrt{49a}\)

\(=3\sqrt{a}-4\sqrt{a}+7\sqrt{a}\)

\(=\left(3-4+7\right)\sqrt{a}\)

\(=6\sqrt{a}\)

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

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

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

Answer 2

Gấp nha