化簡下列各式:
1.√80 - 2√20
2.√24 - √54 + √96
3. √108 + 2√128 - √147
√ = 開方
(超急~唔該!)數3題~~~~~20分20分
2009-02-16 7:44 am
回答 (4)
2009-02-16 7:53 am
✔ 最佳答案
1.√80 - 2√20= 4√5 - 2 (2√5)
= 4√5 - 4√5
= 0
2.√24 - √54 + √96
= 2√6 - 3√6 + 4√6
= 3√6
3.√108 + 2√128 - √147
= 6√3 + 2 ( 8√2) - 7√3
= 16√2 - √3
2009-02-20 8:12 am
1.√80 - 2√20
=√2x2x20 - 2√20
=2√20 - 2√20
=0
2.√24 - √54 + √96
=√2x2x6 - √6x3x3 + √4x4x6
=2√6 - 3√6 + 4√6
3√6
3.√108 + 2√128 - √147
=√3x6x6 +2 √4x4x2x2x2 - √3x7x7
=6√3 +16 √2 - 7√3
=16√2 - √3
=√2x2x20 - 2√20
=2√20 - 2√20
=0
2.√24 - √54 + √96
=√2x2x6 - √6x3x3 + √4x4x6
=2√6 - 3√6 + 4√6
3√6
3.√108 + 2√128 - √147
=√3x6x6 +2 √4x4x2x2x2 - √3x7x7
=6√3 +16 √2 - 7√3
=16√2 - √3
參考: handworks
2009-02-17 12:02 am
1.√80 - 2√20
= √(4×20) - 2√20
= √4 × √20 - 2√20
= 2√20 - 2√20
= 0
2.√24 - √54 + √96
= √(4×6) - √(9×6) + √(16×6)
= √4 × √6 - √9 × √6 + √16 × √6
= 2√6 - 3√6 + 4√6
= 3√6
3.√108 + 2√128 - √147
= √(36×3) + 2√(2^7) - √(49×3) ......... ^ = 次方
= √36 × √3 + 2√(2^6)(2) - √49 × √3
= 6√3 + 2√2^6 × √2 - 7√3
= 6√3 + 2(2^3) × √2 - 7√3
= 6√3 + (2^4)√2 - 7√3
= 16√2 - √3
= √(4×20) - 2√20
= √4 × √20 - 2√20
= 2√20 - 2√20
= 0
2.√24 - √54 + √96
= √(4×6) - √(9×6) + √(16×6)
= √4 × √6 - √9 × √6 + √16 × √6
= 2√6 - 3√6 + 4√6
= 3√6
3.√108 + 2√128 - √147
= √(36×3) + 2√(2^7) - √(49×3) ......... ^ = 次方
= √36 × √3 + 2√(2^6)(2) - √49 × √3
= 6√3 + 2√2^6 × √2 - 7√3
= 6√3 + 2(2^3) × √2 - 7√3
= 6√3 + (2^4)√2 - 7√3
= 16√2 - √3
參考: me
2009-02-16 7:56 am
1.
√80 - 2√20
=2√20-2√20
=0
2.
√24 - √54 + √96
=2√6-3√6+4√6
=3√6
3.
√108 + 2√128 - √147
=6√3+16√2-7√3
=16√2-√3
√80 - 2√20
=2√20-2√20
=0
2.
√24 - √54 + √96
=2√6-3√6+4√6
=3√6
3.
√108 + 2√128 - √147
=6√3+16√2-7√3
=16√2-√3
收錄日期: 2021-04-26 13:14:37
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090215000051KK02620