Question 1105239
Let {{{ s }}} = the speed in mi/hr of the plane in still air
Let {{{ c }}} = the speed in mi/hr of the wind
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{{{ s - c = 1015/7 }}}
{{{ s + c = 820/4 }}}
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{{{ s - c = 145 }}}
{{{ s + c = 205 }}}
Add the equations
{{{ 2s = 350 }}}
{{{ s = 175 }}}
and
{{{ s + c = 205 }}}
{{{ 175 + c = 205 }}}
{{{ c = 30 }}}
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The speed of the plane in still air is 175 mi/hr
The speed of the wind is 30 mi/hr
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