Answer: [tex]\bold{C)\ 15\sqrt2}[/tex]
Step-by-step explanation:
Simply each radical (groups of two factors on the side, make one factor on the outside). Then add the like terms (same radical).
[tex]\sqrt{8}+\sqrt{98}+\sqrt{72}\\\\=\sqrt{2\cdot 2\cdot 2}+\sqrt{2\cdot 7\cdot 7}+\sqrt{2\cdot 6\cdot 6}\\\\=2\sqrt{2}+7\sqrt{2}+6\sqrt{2}\\\\=(2+7+6)\sqrt2\\\\=15\sqrt2[/tex]
