$4\sqrt{21}+6\sqrt{21}=? A242124\sqrt{21}2421B31C102110\sqrt{21}1021D42Answer: 102110\sqrt{21}1021 Read Explanation: am+bm=(a+b)ma\sqrt{m}+b\sqrt{m}=(a+b)\sqrt{m}am+bm=(a+b)m 421+621=10214\sqrt{21}+6\sqrt{21}=10\sqrt{21}421+621=1021 Read more in App