Question 701024
{{{ d = r*t }}}
given:
{{{ d = 15 }}} km
{{{ t = x }}} hrs
{{{ r = x + 2 }}} km/hr
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{{{ 15 = ( x + 2 )*x }}}
{{{ 15 = x^2 + 2x }}}
{{{ x^2 + 2x - 15 = 0 }}}
{{{ ( x + 5 )*( x - 3 ) = 0 }}}
{{{ x = 3 }}} ( ignore the negative answer )