We know what she is earning now and that it is 9% more than what she used to earn.
The $1711.30 is 109% of what number? There is your equation in words.
The new salary is all of (100%) plus and extra 9% which = 109%
Now to put it into math:
$1711.30 = 1.09n (is means =) (of means times and a number next to a variable with no sign between is related by multiplication
$1711.30 = 1.09n
1.09 1.09 I divided both sides by 1.09
n = $1570 - her old salary before the increase. Hope I helped.
