we are given
Account balance on 1 st August was $1,025
so,

During August, supplies of $3,110 were purchased
so,
purchase =3110
$1,324 of supplies were on hand as of August 31
so, EB=1324
Let's assume supplies expense for August as X
so, we can use formula

now, we can plug values
we get

now, we can solve for X
we get

so,
The supplies expense for August is $2811.........Answer