Kerjain yg a sama b yaaaaa

Materi: Bentuk Pangkat.
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a)
[tex](a ^{-1} + b ^{-1}) ^{-1} \\ =( \frac{1}{a}+ \frac{1}{b} ) ^{-1} \\ = (\frac{b}{ab}+ \frac{a}{ab}) ^{-1} \\ =( \frac{b+a}{ab}) ^{-1} \\ = \frac{ \frac{1}{b+a} }{ \frac{1}{ab} } \\ = \frac{1}{b+a} . \frac{ab}{1} \\ = \frac{ab}{b+a} [/tex]

b)
[tex] \frac{a^{-2}+b^{-1} }{a ^{-1} +b ^{-2} } \\ = \frac{ \frac{1}{a^{2} }+ \frac{1}{b} }{ \frac{1}{a} + \frac{1}{b ^{2} } } \\ =\frac{ \frac{b}{a^{2}b }+ \frac{a ^{2} }{a ^{2} b} }{ \frac{b ^{2} }{ab ^{2} } + \frac{a}{ab ^{2} } } \\ = \frac{ \frac{a ^{2} +b}{a ^{2}b } }{ \frac{a+b ^{2} }{ab ^{2} } } \\ = \frac{a ^{2}+b }{a ^{2}b } . \frac{ab ^{2} }{a+b ^{2} } \\ = \frac{b(a ^{2}+b )}{a(a+b ^{2}) } [/tex]