Question 1015573
What is Ben's head start in miles?
{{{ d[1] = 2*1.5 }}}
{{{ d[1] = 3 }}} mi
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Let {{{ d }}} = distance Amanda travels 
until she catches up to Ben
Start a stop watch when Amanda leaves
Let {{{ t }}} = time on stopwatch when
she catches up with Ben
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Ben's equation
(1) {{{ d - 3 = 2t }}}
Amanda's equation:
(2) {{{ d = 4t }}}
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Substitute (2) into (1)
(1) {{{ 4t - 3 = 2t }}}
(1) {{{ 2t = 3 }}}
(1) {{{ t = 3/2 }}}
She catches up to Ben in 1.5 hrs
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check:
(2) {{{ d = 4t }}}
(2) {{{ d = 4*1.5 }}}
(2) {{{ d = 6 }}} mi
and
(1) {{{ d - 3 = 2t }}}
(1) {{{ d - 3 = 2*1.5 }}}
(1) {{{ d - 3 = 3 }}}
(1) {{{ d = 6 }}}
OK