Question 1040323
{{{ 1/128 = 1/(( 2^7)) }}}
{{{ 1/128 = 2^(-7) }}}
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{{{ 8^x = 2^(-7) }}}
{{{ ( 2^3 )^x= 2^(-7) }}}
{{{ 2^(3x) = 2^(-7) }}}
The exponents have to be equal
{{{ 3x = -7 }}}
{{{ x = -7/3 }}}
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Check the answer:
{{{ 8^x = 1/128 }}}
{{{ 8^(-7/3) = 1/128 }}}
{{{ 8^(-2.3333) = .0078125 }}}
{{{ .007813 = .0078125 }}}
error due to rounding off