Question 423139
Ellen's equation:
{{{ d = 12*t }}}
Kate's equation:
{{{ d = 9*(t + .25) }}}
---------------
By substitution:
{{{12t = 9t + 2.25 }}}
{{{ 3t = 2.25 }}}
{{{ t = .75 }}}
Ellen got to the library in .75 hrs or 45 min
check answer:
{{{d = 12*.75 }}}
{{{ d = 9 }}}
and
{{{ d = 9*(.75 + .25) }}}
{{{d = 9}}}
OK