Question

Упростить
b^-7/b^-4*b^-2 при b=-1/5

Answer 1

$frac{b^{-7}}{b^{-4}*b^{-2}}=b^{-7-(-4-2)}=b^{-7+6}=b^{-1}= frac{1}{b} \ frac{1}{b} =frac{1}{ frac{-1}{5} }=-5$

Answer 2

$frac{b^{-7} }{b^{-5}} *b^{-2}=b^{-7-(-5)-2}=b^{-4}\\b= -frac{1}{5}\\(- frac{1}{5})^{-4}=(-5)^4=625$