7. $\sqrt{5} \div \sqrt{10}$ 8. $-\sqrt{75} \div \sqrt{45}$ 9. $2\sqrt{21} \div \sqrt{3}$ 10. $-\sqrt{32} \div 2\sqrt{2}$ 11. $-5\sqrt{3} \div \sqrt{15}$ 12. $-7\sqrt{2} \div (-\sqrt{28})$

はい、承知いたしました。画像にある問題すべて解きます。

1. 問題の内容

7. $\sqrt{5} \div \sqrt{10}$

8. $-\sqrt{75} \div \sqrt{45}$

9. $2\sqrt{21} \div \sqrt{3}$

1

0. $-\sqrt{32} \div 2\sqrt{2}$

1

1. $-5\sqrt{3} \div \sqrt{15}$

1

2. $-7\sqrt{2} \div (-\sqrt{28})$

2. 解き方の手順

7. $\sqrt{5} \div \sqrt{10} = \frac{\sqrt{5}}{\sqrt{10}} = \sqrt{\frac{5}{10}} = \sqrt{\frac{1}{2}} = \frac{1}{\sqrt{2}} = \frac{\sqrt{2}}{2}$

8. $-\sqrt{75} \div \sqrt{45} = -\frac{\sqrt{75}}{\sqrt{45}} = -\sqrt{\frac{75}{45}} = -\sqrt{\frac{5}{3}} = -\frac{\sqrt{5}}{\sqrt{3}} = -\frac{\sqrt{15}}{3}$

9. $2\sqrt{21} \div \sqrt{3} = \frac{2\sqrt{21}}{\sqrt{3}} = 2\sqrt{\frac{21}{3}} = 2\sqrt{7}$

1

0. $-\sqrt{32} \div 2\sqrt{2} = -\frac{\sqrt{32}}{2\sqrt{2}} = -\frac{\sqrt{16 \cdot 2}}{2\sqrt{2}} = -\frac{4\sqrt{2}}{2\sqrt{2}} = -2$

1

1. $-5\sqrt{3} \div \sqrt{15} = -\frac{5\sqrt{3}}{\sqrt{15}} = -5\sqrt{\frac{3}{15}} = -5\sqrt{\frac{1}{5}} = -\frac{5}{\sqrt{5}} = -\sqrt{5}$

1

2. $-7\sqrt{2} \div (-\sqrt{28}) = \frac{-7\sqrt{2}}{-\sqrt{28}} = \frac{7\sqrt{2}}{\sqrt{4 \cdot 7}} = \frac{7\sqrt{2}}{2\sqrt{7}} = \frac{7}{2}\sqrt{\frac{2}{7}} = \frac{7}{2}\sqrt{\frac{14}{49}} = \frac{7}{2} \frac{\sqrt{14}}{7} = \frac{\sqrt{14}}{2}$

3. 最終的な答え

7. $\frac{\sqrt{2}}{2}$

8. $-\frac{\sqrt{15}}{3}$

9. $2\sqrt{7}$

1

0. $-2$

1

1. $-\sqrt{5}$

1

2. $\frac{\sqrt{14}}{2}$