tentukan hasil dari [tex] 2 \sqrt{18 } + \sqrt{50} - \sqrt{98} [/tex]

[tex] = 2 \sqrt{18} + \sqrt{50} - \sqrt{98 } \\ = 2 \sqrt{ {3}^{2} \times 2 } + \sqrt{ {5}^{2} \times 2} \times - \sqrt{ {7}^{2} \times 2 } \\ = (2 \times 3+ 5 - 7) \sqrt{2} \\ = (6 + 5 - 7) \sqrt{2} \\ = 4 \sqrt{2} [/tex]