a) \(\sqrt{20}+\sqrt{45}-\sqrt{5}\)
\(=2\sqrt{5}+3\sqrt{5}-\sqrt{5}\)
\(=4\sqrt{5}\)
b) \(\sqrt{121}+\sqrt{81}-\sqrt{16}\)
\(=11+9-4\)
\(=16\)
a) √20+√45−√5
=2√5+3√5−√5
=4√5=45
b) √121+√81−√16
=11+9−4
=16
Hồi nãy lỗi đánh máy
a) \(\sqrt{20}\) + \(\sqrt{45}\) - \(\sqrt{5}\)
= 2\(\sqrt{5}\) + \(3\sqrt{5}\) - \(\sqrt{5}\)
= \(4\sqrt{5}\)
b) \(\sqrt{121}\) + \(\sqrt{81}\) - \(\sqrt{16}\)
= 11 + 9 - 4
= 20 - 4
= 16