The equation y = 21.2x represents Maya's earnings in dollars and cents, y, for working x hours. Xavier earned $680.20 in 38 hours.
we have that
Maya's earning are
$21.2 per hour --------> hourly rate is the same that the slope of the linear equation
Xavier
Find the hourly rate
Divide $680.20 by 38 hours
so
$680.20/38=$17.9 per hour
Find the difference
-$21.2 -$17.9=$3.30
therefore
Maya earns $3.30 per hour more than Xavier