Question

A college student earned $246, $288, $234, and $ 276 over a four week period. How much he earn during the fifth week to have average earnings of $255 for the five weeks?

Answer 1

The equation here is

$\frac{246 + 288 + 234 + 276 + x}{5} = 255$
If we multiply both sides by 5 we get
$246 + 288 + 234 + 276 + x = 1275$
Now if we add our like terms, we get
$1044 + x = 1275$
Now lets subtract 1044 from both sides to get a value for x
$x = 231$