Question 1099330
Let {{{ s }}} = the speed of the plane in still air
Let {{{ w }}} = the speed of the wind
------------------------------------
Flying with the wind:
(1) {{{ 2655 = ( s + w )*4.5 }}}
Flying against the wind:
(2) {{{ 2115 = ( s - w )*4.5 }}}
-------------------------------
Add the equations
(1) {{{ 4.5s + 4.5w = 2655 }}}
(2) {{{ 4.5s - 4.5w = 2115 }}}
--------------------------------
{{{ 9s = 4770 }}}
{{{ s = 530 }}}
and
(1) {{{ 4.5s + 4.5w = 2655 }}}
(1) {{{ 4.5*530 + 4.5w = 2655 }}}
(1) {{{ 2385 + 4.5w = 2655 }}}
(1) {{{ 4.5w = 270 }}}
(1) {{{ w = 60 }}}
-----------------------
The speed of the plane in still air is 530 mi/hr
The speed of the wind is 60 mi/hr
--------------------------------------------
check:
(1) {{{ 2655 = ( 530 + 60 )*4.5 }}}
(1) {{{ 2655 = 590*4.5 }}}
(1) {{{ 2655 = 2655 }}}
You can check (2)