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why does (3/4)^-2 gives 16/9? Isn't it suppose to be 9/16?

 Jun 20, 2015

Best Answer 

 #1
avatar+125 
+8

$${\left({\frac{{\mathtt{3}}}{{\mathtt{4}}}}\right)}^{\left(-{\mathtt{2}}\right)} = {\left({\left({\frac{{\mathtt{3}}}{{\mathtt{4}}}}\right)}^{{\mathtt{2}}}\right)}^{\left(-{\mathtt{1}}\right)}$$

$${\left({\frac{{\mathtt{9}}}{{\mathtt{16}}}}\right)}^{-{\mathtt{1}}} = {\frac{{\mathtt{1}}}{\left({\frac{{\mathtt{9}}}{{\mathtt{16}}}}\right)}}$$

$${\frac{{\mathtt{1}}}{\left({\frac{{\mathtt{9}}}{{\mathtt{16}}}}\right)}} = {\frac{{\mathtt{16}}}{{\mathtt{9}}}}$$

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 Jun 20, 2015
 #1
avatar+125 
+8
Best Answer

$${\left({\frac{{\mathtt{3}}}{{\mathtt{4}}}}\right)}^{\left(-{\mathtt{2}}\right)} = {\left({\left({\frac{{\mathtt{3}}}{{\mathtt{4}}}}\right)}^{{\mathtt{2}}}\right)}^{\left(-{\mathtt{1}}\right)}$$

$${\left({\frac{{\mathtt{9}}}{{\mathtt{16}}}}\right)}^{-{\mathtt{1}}} = {\frac{{\mathtt{1}}}{\left({\frac{{\mathtt{9}}}{{\mathtt{16}}}}\right)}}$$

$${\frac{{\mathtt{1}}}{\left({\frac{{\mathtt{9}}}{{\mathtt{16}}}}\right)}} = {\frac{{\mathtt{16}}}{{\mathtt{9}}}}$$

syllogist Jun 20, 2015
 #2
avatar+128475 
+5

Remember......when we have this situation (a/b)^(-m).....where a/b ≠ 0...we can  "flip"  the fraction and make the expononent positive.....so......

 

(3/4)^(-2)   =     (4/3)^2  =   (16/9)

 

 

 Jun 20, 2015

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