simplify:- root45/root125?

2009-06-17 3:12 pm

回答 (11)

2009-06-17 3:16 pm
✔ 最佳答案
[ - sqr (45) ] / [ sqr (125) ] =

[- sqr (9) * sqr (5) ] / [ (sqr (25) * sqr (5) ] =

[ - 3 * sqr (5) ] / [ 5 * sqr (5) ] =

- 3/5

*******
2009-06-17 3:32 pm
3/5
2009-06-17 3:28 pm
√ 45
------
√ 125

3√ 5
--------------
5√ 5

3
----
5

PS
I think that your :- sign is being taken as a - ve sign by some.
2009-06-17 3:21 pm
root A/root B = root (A/B)

root 45/root 125 = root (45/125)
= root (9/25)
2009-06-17 3:21 pm
-√45/(√125)
= -√(3^2 * 5)/[√(5^2 * 5)]
= -[√(3^2) * √5]/[√(5^2) * √5]
= -[3 * √5]/[5 * √5]
= -3/5
2009-06-17 3:20 pm
45 = 9*5 so root 45=root(9*5)=3root5
root125=root(25*5)=5root5
root45/root125=3root5/5root5=3/5
2009-06-17 3:20 pm
is that a negative?

- 3/5sqrt5
2009-06-17 3:19 pm
=-3sqrt(5)/5sqrt(5)
=-3/5
2009-06-17 3:18 pm
Cancel root5 to end up with 3/5
2009-06-17 3:16 pm
3/5


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