Question 905927
Let {{{ d }}} = the distance in km the faster plane travels in km
{{{ 6892 - d }}} = the distance the slower plane travels in km
Let {{{ s }}} = the speed of the faster plane in km/hr
{{{ s - 75 }}} = the speed of the slower plane in km/hr
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Equation for faster plane:
(1) {{{ d = s*4 }}}
Equation for slower plane:
(2) {{{ 6892 - d = ( s - 75 )*4 }}}
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Substitute (1) into (2)
(2) {{{ 6892 - 4s = ( s - 75 )*4 }}}
(2) {{{ 6892 - 4s = 4s - 300 }}}
(2) {{{ 8s = 7192 }}}
(2) {{{ s = 899 }}}
and
{{{ s - 75 = 824 }}}
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The speed of the faster plane is 899 km/hr
The speed of the slower plane is 824 km/hr
check:
(2) {{{ 6892 - d = ( s - 75 )*4 }}}
(2) {{{ 6892 - d = 824*4 }}}
(2) {{{ d = 6892 - 3296 }}}
(2) {{{ d = 3596 }}}
and
(1) {{{ d = s*4 }}}
(1) {{{ d = 899*4 }}}
(1) {{{ d = 3596 }}}
OK