trustno1
the good girl gone bad
yeah, it'd be cool. if anyone else needs math help(not higher than algebra 2) I'd be happy to help, and I'm sure their are others who would be too
Originally posted by Khaych
1:
Radical 75q^11
Radical (3 * 25 * q^11)
5 * Radical (3 * q^2 * q^2 * q^2 * q^2 * q^2 * q)
5 * Radical (3q) * q * q * q * q * q
5 * Radical (3q) * q^5
5q^5 * Radical (3q)
this was the long way of doing it
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2.
radical 12(r^6)(s^7)
radical [3 * 4(r^6)(s^6)s]
2(r^3)(s^3) * radical (3s)
you can see that when an exponent within the radical is even, dividing it by two will give you the proper exponent outside of the radical. I could have done it the long way:
radical [3 * 4(r^6)(s^7)]
radical (3 * 4 * r * r * r * r * r * r * s * s * s * s * s * s * s)
and then grouped them into perfect squares
radical (3 * 4 * r^2 * r^2 * r^2 * s^2 *s^2 * s^2 * s)
seperated them all into seperate radicals:
radical (3s) * radical (4) * radical (r^2) * radical (r^2) * radical (r^2) * radical (s^2) * radical (s^2) * radical (s^2)
then resolved the perfect squares:
radical (3s) * 2 * r * r * r * s * s * s
Then put all the r's and s's into exponent form
radical (3s) * 2 * r^3 * s^3
2(r^3)(s^3) * radical (3s)
...same answer, but that's the long way, and it's alot of extra writing.
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9:
2 radical (7/25) ------just guessing this is where the parentheses are--------------
2 radical (7) / radical (25)
2 radical (7) / 5
(2/5) radical (7)
The trick in that last one is that whenever you have a fraction in a radical, you can split the radical top and bottom, so radical (7/25) becomes (radical 7) / (radical 25).
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10:
5 radical (9 / 196)
5 * radical (9) / radical (196)
both of these radicals are perfect squares!
5 * (3 / 14)
15 / 14
1 + 1/14
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20.
radical 2 * radical (3 +3) -----did I get the parentheses right?---
radical 2 * radical 6
radical (2 * 6)
radical (12)
radical (3 * 4)
radical (4) * radical (3)
2 radical (3)
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21. (this one's a little harder)
(8 + radical 7) (8 - radical 7)
FOIL it. It's a binomial, just like in algebra
64 - (8 * radical 7) + (8 * radical 7) - (radical 7)(radical 7)
the middle two cancel out (one's plus, the other minus)
64 - (radical 7)(radical 7)
64 - radical (7 * 7)
64 - radical (49) ---49 is a perfect square----
64 - 7
57
<or you could have just used the Difference of Squares formula, if you remember it from algebra, to finish the question a little quicker, where (a+b)(a-b) = (a^2) - (b^2)>
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Does any of this make any sense? I know I'm not a good teacher, so if anyone sees a better way to explain it, please do...