~F.2 maths

2007-03-28 3:14 am

1. (√3 - √2)(√3 + √2)
2. (√2 + √5)(√2 + √5)

回答 (4)

2007-03-28 3:21 am

✔ 最佳答案

1.
(√3 - √2)(√3 + √2)
=√3(√3 + √2)- √2(√3 + √2)
=3+√6-√6-2
=3-2=1
2.
(√2 + √5)(√2 + √5)
=√2(√2 + √5)+ √5(√2 + √5)
=2+√10+√10+5
=7+2√10

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2007-03-28 3:26 am

1.(√3-√2)(√3+√2)
=(√3-√2)^2
=3-2
=1
2.(√2+√5)(√2+√5)
=2+2√2‧√ 5+5

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2007-03-28 3:26 am

1. 3 - 2 = 1
2. (√2 + √5)的二次方，再等於　２＋２√１０＋５，再等於７＋２√１０

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2007-03-28 3:19 am

1. (√3 - √2)(√3 + √2)
= (√3)^2 - (√2)^2
= 3 - 2
= 1

2. (√2 + √5)(√2 + √5)
= (√2)^2 + 2(√2)(√5) + (√5)^2
= 2 + 2√10 + 5
= 7 + 2√10

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