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~~~~~10分10分
2009-02-16 7:45 am
回答 (3)
2009-02-16 8:10 am
✔ 最佳答案
1.√80 - 2√20
= √(4^2 x 5) - 2√(2^2 x 5)
= 4√5 - 4√5
= 0
2.
√24 - √54 + √96
= √(2^2 x 6) - √(3^2 x 6) + √(4^2 x 6)
= 2√6 - 3√6 + 4√6
= (2 - 3 + 4)√6
= 3√6
3.
√108 + 2√128 - √147
= √(6^2 x 3) + 2√(8^2 x 2) - √(7^2 x 3)
= 6√3 + 16√2 - 7√3
= 16√2 - √3
2009-02-18 3:58 pm
1)√80 - 2√20
=√2*2*2*2*5 - 2√2*2*5
=2^2√5 - 2*2√5
=4√5 - 4√5
=0
2)√24- √54 +√96
=√2*2*2*3 - √2*3*3*3 + √2*2*2*2*2*3
=2√2*3 - 3√2*3 + 2^2√2*3
=2√6 - 3√6 + 4√6
=3√6
3)√108 + 2√128 - √147
=√2*2*3*3*3 + 2√2*2*2*2*2*2*2 - √3*7*7
=2*3√3 + 2*2*2*2√2 - 7√3
=6√3 + 16√2 - 7√3
=16√2-√3
I hope I can help you.
=√2*2*2*2*5 - 2√2*2*5
=2^2√5 - 2*2√5
=4√5 - 4√5
=0
2)√24- √54 +√96
=√2*2*2*3 - √2*3*3*3 + √2*2*2*2*2*3
=2√2*3 - 3√2*3 + 2^2√2*3
=2√6 - 3√6 + 4√6
=3√6
3)√108 + 2√128 - √147
=√2*2*3*3*3 + 2√2*2*2*2*2*2*2 - √3*7*7
=2*3√3 + 2*2*2*2√2 - 7√3
=6√3 + 16√2 - 7√3
=16√2-√3
I hope I can help you.
2009-02-17 12:00 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
收錄日期: 2021-04-13 16:26:23
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090215000051KK02626