Question 474762
These are all similar.
Do it like this one.
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{{{(2b^-7c^4)^4 / 5^-1b^2c^6 }}}
= {{{16b^-28c^16 / 5^-1b^2c^6}}}
= {{{80b^-28c^16 / b^2c^6}}}
Multiply by {{{b^28/b^28}}}
= {{{80c^16 / b^30c^6}}}
Cancel c^6
= {{{80c^10 / b^30}}}