3√2 x 5√10 Simplified?

👨🏻‍🏫 學術台數學

[匿名]

2009-05-04 11:10 am

Okay, here's the question: Simplify: 3√2 x 5√10

I keep getting 15√20

The book the question is in says the answer is 30√5
If that's the answer, how do you go about getting that?

If I was right, let me know, though.. I just want to know so that I can know how to approach those sort of questions in the future.

Please help, thanks.

更新1:

Oh, thank you! Very much appreciated.

回答 (8)

[匿名]

2009-05-04 11:16 am

✔ 最佳答案

15√20
= 15√(4*5)
= 15√4√5
= 15*2√5
= 30√5

to reduce a surd like √20 to its simplest form, you look for the biggest square 1,4,9,16, etc that divides 20 which in this case is 4
As another example, if you had √72 then the biggest square that divides 72 is 36 so you could write this as √72 = √36√2 = 6√2 which is its simplest form
,.,.,

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[匿名]

2009-05-04 11:16 am

================================
those are both right
radical 20 is also radical 5 times radical 4
radical 4 becomes 2
so 15 x 2 rad 5
30 rad 5
================================

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[匿名]

2016-10-19 7:37 pm

10(m-3)+2(5-3n)-4(-4m-7n-9) -> 10m-30 +10-6n +16m+28n+36 assemble like time period -> 10m+16m+28n-6n-30+10+36 -------------------------->26m+22n+16 is your very last answer (8x+y)/x, at the same time as x=7/2 and y=7 -> first do 8*(7/2)+7 = (fifty six/2) +7 = 28+7 =35 -> then 35/(7/2) = 35/3.5=10 in case you won't be able to attempt this you're in problem. What grade are you in? i'm hoping that is sixth grade or decrease.

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[匿名]

2009-05-04 11:38 am

3√2 x 5√10 = 3 * 5 * √2 * √10
= 15√20
= 15 √(5*4)
= 15 * 2 * √5
= 30√5

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An ESL Learner

2009-05-04 11:34 am

3√2 x 5√10
= (3 x 5)√(2 x 10)
= 15√20
= 15√(2^2 x 5)
= 15 x √(2^2) x √5
= 15 x 2 x √5
= 30√5

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nozar nazari

2009-05-04 11:25 am

3\/'''2''' x 5\/'''5'' x \/'''2''=30\/''''5'''
your answer is correct too,because 15(2x2x5)^1/2=30\/'''5''''.

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[匿名]

2009-05-04 11:21 am

You're on the right track: remember that:

√20

= √(4 x 5)

= √4 x √5

= 2√5

So,

15√20

= 15 x 2√5

= 30√5

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[匿名]

2009-05-04 11:20 am

20=5x4 & square root of 4 is 2 .as simplification in surds mean take out all parts out of root sign.so the text book result is OK & I hope you followed your mistake.

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