与えられた平方根の数を $a\sqrt{b}$ の形に変形する問題です。

算数平方根根号平方根の簡約
2025/4/23

1. 問題の内容

与えられた平方根の数を aba\sqrt{b} の形に変形する問題です。

2. 解き方の手順

各問題について、平方根の中の数を素因数分解し、平方数を取り出すことで、aba\sqrt{b} の形に変形します。
(5) 28\sqrt{28}
28=4×7=22×728 = 4 \times 7 = 2^2 \times 7
28=22×7=22×7=27\sqrt{28} = \sqrt{2^2 \times 7} = \sqrt{2^2} \times \sqrt{7} = 2\sqrt{7}
(6) 20\sqrt{20}
20=4×5=22×520 = 4 \times 5 = 2^2 \times 5
20=22×5=22×5=25\sqrt{20} = \sqrt{2^2 \times 5} = \sqrt{2^2} \times \sqrt{5} = 2\sqrt{5}
(7) 72\sqrt{72}
72=36×2=62×272 = 36 \times 2 = 6^2 \times 2
72=62×2=62×2=62\sqrt{72} = \sqrt{6^2 \times 2} = \sqrt{6^2} \times \sqrt{2} = 6\sqrt{2}
(8) 90\sqrt{90}
90=9×10=32×1090 = 9 \times 10 = 3^2 \times 10
90=32×10=32×10=310\sqrt{90} = \sqrt{3^2 \times 10} = \sqrt{3^2} \times \sqrt{10} = 3\sqrt{10}
(9) 125\sqrt{125}
125=25×5=52×5125 = 25 \times 5 = 5^2 \times 5
125=52×5=52×5=55\sqrt{125} = \sqrt{5^2 \times 5} = \sqrt{5^2} \times \sqrt{5} = 5\sqrt{5}
(10) 112\sqrt{112}
112=16×7=42×7112 = 16 \times 7 = 4^2 \times 7
112=42×7=42×7=47\sqrt{112} = \sqrt{4^2 \times 7} = \sqrt{4^2} \times \sqrt{7} = 4\sqrt{7}
(11) 50\sqrt{50}
50=25×2=52×250 = 25 \times 2 = 5^2 \times 2
50=52×2=52×2=52\sqrt{50} = \sqrt{5^2 \times 2} = \sqrt{5^2} \times \sqrt{2} = 5\sqrt{2}
(12) 63\sqrt{63}
63=9×7=32×763 = 9 \times 7 = 3^2 \times 7
63=32×7=32×7=37\sqrt{63} = \sqrt{3^2 \times 7} = \sqrt{3^2} \times \sqrt{7} = 3\sqrt{7}
(13) 44\sqrt{44}
44=4×11=22×1144 = 4 \times 11 = 2^2 \times 11
44=22×11=22×11=211\sqrt{44} = \sqrt{2^2 \times 11} = \sqrt{2^2} \times \sqrt{11} = 2\sqrt{11}
(14) 500\sqrt{500}
500=100×5=102×5500 = 100 \times 5 = 10^2 \times 5
500=102×5=102×5=105\sqrt{500} = \sqrt{10^2 \times 5} = \sqrt{10^2} \times \sqrt{5} = 10\sqrt{5}
(15) 48\sqrt{48}
48=16×3=42×348 = 16 \times 3 = 4^2 \times 3
48=42×3=42×3=43\sqrt{48} = \sqrt{4^2 \times 3} = \sqrt{4^2} \times \sqrt{3} = 4\sqrt{3}
(16) 96\sqrt{96}
96=16×6=42×696 = 16 \times 6 = 4^2 \times 6
96=42×6=42×6=46\sqrt{96} = \sqrt{4^2 \times 6} = \sqrt{4^2} \times \sqrt{6} = 4\sqrt{6}
(1) 8\sqrt{8}
8=4×2=22×28 = 4 \times 2 = 2^2 \times 2
8=22×2=22×2=22\sqrt{8} = \sqrt{2^2 \times 2} = \sqrt{2^2} \times \sqrt{2} = 2\sqrt{2}
(2) 12\sqrt{12}
12=4×3=22×312 = 4 \times 3 = 2^2 \times 3
12=22×3=22×3=23\sqrt{12} = \sqrt{2^2 \times 3} = \sqrt{2^2} \times \sqrt{3} = 2\sqrt{3}
(3) 24\sqrt{24}
24=4×6=22×624 = 4 \times 6 = 2^2 \times 6
24=22×6=22×6=26\sqrt{24} = \sqrt{2^2 \times 6} = \sqrt{2^2} \times \sqrt{6} = 2\sqrt{6}
(4) 18\sqrt{18}
18=9×2=32×218 = 9 \times 2 = 3^2 \times 2
18=32×2=32×2=32\sqrt{18} = \sqrt{3^2 \times 2} = \sqrt{3^2} \times \sqrt{2} = 3\sqrt{2}

3. 最終的な答え

(1) 222\sqrt{2}
(2) 232\sqrt{3}
(3) 262\sqrt{6}
(4) 323\sqrt{2}
(5) 272\sqrt{7}
(6) 252\sqrt{5}
(7) 626\sqrt{2}
(8) 3103\sqrt{10}
(9) 555\sqrt{5}
(10) 474\sqrt{7}
(11) 525\sqrt{2}
(12) 373\sqrt{7}
(13) 2112\sqrt{11}
(14) 10510\sqrt{5}
(15) 434\sqrt{3}
(16) 464\sqrt{6}