Question 962962
{{{ log( 2,30 ) - log( 2,12 ) - log( 2,20 ) }}}
Use the rule:
{{{ log( a ) - log( b ) = log(( a/b )) }}}
{{{ log( 2, (30/12) ) - log( 2,20 ) }}}
{{{ log( 2, (5/2) ) - log( 2,20 ) }}}
{{{ log( 2, (5/(2*20)) ) }}}
{{{ log( 2, (1/8) ) }}}
Now I will say:
{{{ y = log( 2, (1/8 )) }}}
{{{ 2^y = 1/8 }}}
{{{ 2^y = 2^(-3) }}}
{{{ y = -3 }}}
Now I can say:
{{{ log( 2, (1/8 )) = -3 }}}