Simplify. square root of 7 over fourth root of 7 7 to the power of negative 3 over 4 7 to the power of 1 over 4 7 to the power of 3 over 4 7
\[\sqrt[b]{x^a} = x^{\frac{ a }{ b }}\] \[\frac{ x^a }{ x^b } = x^{a-b}\]
Use these rules.
i'm not sure how to get the problem to look like that, though.
Let's break it down then, what is the square root of 7 according to the first rule?
\(\Large { \cfrac{\sqrt[2]{7}}{\sqrt[4]{7}} \\ \quad \\ \quad \\ a^{\frac{{\color{blue} n}}{{\color{red} m}}} \implies \sqrt[{\color{red} m}]{a^{\color{blue} n}} \qquad \qquad \sqrt[{\color{red} m}]{a^{\color{blue} n}}\implies a^{\frac{{\color{blue} n}}{{\color{red} m}}} \\\quad \\ % ----------------------------- \cfrac{1}{\sqrt[{\color{red} m}]{a^{\color{blue} n}}}= \cfrac{1}{a^{\frac{{\color{blue} n}}{{\color{red} m}}}}\implies a^{-\frac{{\color{blue} n}}{{\color{red} m}}}\qquad thus \\ \quad \\ \cfrac{\sqrt[2]{7^1}}{\sqrt[4]{7^1}}\implies \cfrac{7^{\frac{1}{2}}}{7^{\frac{1}{4}}}\implies \cfrac{7^{\frac{1}{2}}}{1}\cdot \cfrac{1}{7^{\frac{1}{4}}}\implies 7^{\frac{1}{2}}\cdot 7^{-\frac{1}{4}} }\)
Or just look at this very descriptive explanation.
so... simpify that... recall your exponent rules
it is a very good explanation. thank you. how would i solve it ?
use the exponent rules, check your material on that or just check this rules set http://ts3.mm.bing.net/th?id=HN.607986448326853914&pid=15.1&P=0
when multiplying two bases, different exponent keep the base, sum the exponents
well when multiplying two SAME bases, different exponent keep the base, sum the exponents
so...i would be adding the exponents, then ? and i'd need to make the denominators the same ?
yes... since they're fractions so you'd be adding the fractions, yes, so yo'd get the LCD \(\large { \cfrac{\sqrt[2]{7^1}}{\sqrt[4]{7^1}}\implies \cfrac{7^{\frac{1}{2}}}{7^{\frac{1}{4}}}\implies \cfrac{7^{\frac{1}{2}}}{1}\cdot \cfrac{1}{7^{\frac{1}{4}}}\implies 7^{\frac{1}{2}}\cdot 7^{-\frac{1}{4}}\implies 7^{\frac{1}{2}-\frac{1}{4}} }\)
the lcd is 8, right ?
you could use 8, sure, is not the LCD, but doesn't matter since it'd be simplified anyway
oh, okay, so then the answer is 7^1/4, right ?
yeap
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