Question 468422
Let {{{ t }}} = the time it takes to get to work
given:
Average speed to work = {{{ 20/t }}}
Coming home, the average speed is {{{ 16/t }}}
{{{ 20/t - 7 = 16/t }}}
Multiply both sides by {{{ t }}}
{{{ 20 - 7t = 16 }}}
{{{ 7t = 20 - 16 }}}
{{{ 7t = 4 }}}
{{{ t = 4/7 }}}
The average speed to work is:
{{{ 20 / (4/7) = 20*(7/4) }}}
{{{ 140/4 = 35 }}} mi/hr