Question 1126108
{{{ d = t^2 + 70t }}}
{{{ d = 442.25 }}}
{{{ t^2 + 70t - 442.25 = 0 }}}
{{{ t = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
{{{ a = 1 }}}
{{{ b = 70 }}}
{{{ c = -442.25 }}}
{{{ t = ( -70 +- sqrt( 70^2 - 4*1*(-442.25)))/(2*1) }}}
{{{ t = ( -70 +- sqrt( 4900 + 1769 ) )/2 }}}
{{{ t = ( -70 +- sqrt( 6669 ) )/2 }}}
{{{ t = ( -70 + 81.664 )/2 }}}
{{{ t = 11.664/2 }}}
{{{ t = 5.832 }}}
(a)
5.832 hrs away
(b) {{{ 442.25 = r*5.832 }}}
{{{ r = 75.832 }}} mi/hr
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check my math