Answer
Number of arrivals and departures at
Frankfurt Airport $= 53$ million
London Airport $= 65.9 $million
Paris Airport $= 58.2$ million
Work Step by Step
Let Number of arrivals and departures at Frankfurt airport be $x$.
At London Airport (in millions) $= x+ 12.9 $
At Paris Airport (in millions) $= x+ 5.2$
Total Number of arrivals and departures at three airports $=177.1$ million
$x+x+12.9+x+5.2 = 177.1$
Combine like terms.
$3x+18.1 = 177.1$
Subtract $18.1$ on both sides.
$3x+18.1-18.1 = 177.1-18.1$
$3x=159$
$x=53$
Number of arrivals and departures at
Frankfurt airport (in millions) $= x = 53$
At London Airport (in millions) $= x+ 12.9 $
$=53+ 12.9 $
$= 65.9$
At Paris Airport (in millions) $= x+ 5.2$
$= x+ 5.2 $
$= 53+5.2 $
$= 58.2$
