2 √20- √50+3 √80- √320 √32- √50+ √98- √72 5 √ 3-3 √48+2 √75-1/3 √108 05/07/2021 Bởi Isabelle 2 √20- √50+3 √80- √320 √32- √50+ √98- √72 5 √ 3-3 √48+2 √75-1/3 √108
Đáp án+Giải thích các bước giải: `2\sqrt{20}-\sqrt{50}+3\sqrt{80}-\sqrt{320}` `=2\sqrt{4.5}-\sqrt{25.2}+3\sqrt{16.5}-\sqrt{64.5}` `=2.2.\sqrt{5}-5\sqrt{2}+3.4.\sqrt{5}-8\sqrt{5}` `=4\sqrt{5}-5\sqrt{2}+12\sqrt{5}-8\sqrt{5}` `=(4+12-8)\sqrt{5}-5\sqrt{2}` `=8\sqrt{5}-5\sqrt{2}` _________________ `\sqrt{32}-\sqrt{50}+\sqrt{98}-\sqrt{72}` `=\sqrt{16.2}-\sqrt{25.2}+\sqrt{49.2}-\sqrt{36.2}` `=4\sqrt{2}-5\sqrt{2}+7\sqrt{2}-6\sqrt{2}` `=(4-5+7-6)\sqrt{2}` `=0` _________________ `5\sqrt{3}-3\sqrt{48}+2\sqrt{75}-1/3\sqrt{108}` `=5\sqrt{3}-3\sqrt{16.3}+2\sqrt{25.3}-1/3\sqrt{36.3}` `=5\sqrt{3}-3.4\sqrt{3}+2.5\sqrt{3}-1/3. 6\sqrt{3}` `=5\sqrt{3}-12\sqrt{3}+10\sqrt{3}-2\sqrt{3}` `=(5-12+10-2)\sqrt{3}` `=\sqrt{3}` Bình luận
Đáp án:
Giải thích các bước giải:
Đáp án+Giải thích các bước giải:
`2\sqrt{20}-\sqrt{50}+3\sqrt{80}-\sqrt{320}`
`=2\sqrt{4.5}-\sqrt{25.2}+3\sqrt{16.5}-\sqrt{64.5}`
`=2.2.\sqrt{5}-5\sqrt{2}+3.4.\sqrt{5}-8\sqrt{5}`
`=4\sqrt{5}-5\sqrt{2}+12\sqrt{5}-8\sqrt{5}`
`=(4+12-8)\sqrt{5}-5\sqrt{2}`
`=8\sqrt{5}-5\sqrt{2}`
_________________
`\sqrt{32}-\sqrt{50}+\sqrt{98}-\sqrt{72}`
`=\sqrt{16.2}-\sqrt{25.2}+\sqrt{49.2}-\sqrt{36.2}`
`=4\sqrt{2}-5\sqrt{2}+7\sqrt{2}-6\sqrt{2}`
`=(4-5+7-6)\sqrt{2}`
`=0`
_________________
`5\sqrt{3}-3\sqrt{48}+2\sqrt{75}-1/3\sqrt{108}`
`=5\sqrt{3}-3\sqrt{16.3}+2\sqrt{25.3}-1/3\sqrt{36.3}`
`=5\sqrt{3}-3.4\sqrt{3}+2.5\sqrt{3}-1/3. 6\sqrt{3}`
`=5\sqrt{3}-12\sqrt{3}+10\sqrt{3}-2\sqrt{3}`
`=(5-12+10-2)\sqrt{3}`
`=\sqrt{3}`