次の計算問題を解きます。 (1) $\sqrt{8} \times \sqrt{20}$ (2) $\sqrt{12} \times \sqrt{50}$ (3) $\sqrt{18} \times \sqrt{28}$ (4) $\sqrt{5} \times \sqrt{15}$ (5) $\sqrt{14} \times \sqrt{21}$ (6) $\sqrt{26} \times \sqrt{39}$

1. 問題の内容

次の計算問題を解きます。

(1) $\sqrt{8} \times \sqrt{20}$

(2) $\sqrt{12} \times \sqrt{50}$

(3) $\sqrt{18} \times \sqrt{28}$

(4) $\sqrt{5} \times \sqrt{15}$

(5) $\sqrt{14} \times \sqrt{21}$

(6) $\sqrt{26} \times \sqrt{39}$

2. 解き方の手順

(1) $\sqrt{8} \times \sqrt{20} = \sqrt{8 \times 20} = \sqrt{160} = \sqrt{16 \times 10} = 4\sqrt{10}$

(2) $\sqrt{12} \times \sqrt{50} = \sqrt{12 \times 50} = \sqrt{600} = \sqrt{100 \times 6} = 10\sqrt{6}$

(3) $\sqrt{18} \times \sqrt{28} = \sqrt{18 \times 28} = \sqrt{504} = \sqrt{36 \times 14} = 6\sqrt{14}$

(4) $\sqrt{5} \times \sqrt{15} = \sqrt{5 \times 15} = \sqrt{75} = \sqrt{25 \times 3} = 5\sqrt{3}$

(5) $\sqrt{14} \times \sqrt{21} = \sqrt{14 \times 21} = \sqrt{294} = \sqrt{49 \times 6} = 7\sqrt{6}$

(6) $\sqrt{26} \times \sqrt{39} = \sqrt{26 \times 39} = \sqrt{1014} = \sqrt{169 \times 6} = 13\sqrt{6}$

3. 最終的な答え

(1) $4\sqrt{10}$

(2) $10\sqrt{6}$

(3) $6\sqrt{14}$

(4) $5\sqrt{3}$

(5) $7\sqrt{6}$

(6) $13\sqrt{6}$