Answer
The highest is $39$ bags.
$x \leq 39$
Work Step by Step
First, let $x$ be the number of bags we can lift in one trip safely
Then from the asked problem we have the inequality:
$ 2800 - (265 + 65x) \geq 0$
Next, all we have to do is solve the inequality.
$ 2800 - (265 + 65x) \geq 0$
$ 2800 - 265 - 65x \geq 0$
Add $65x$ on both sides.
$ 2535- 65x + 65x \geq 0 + 65x$
$ 2535 \geq 65x$
Divide with $65$ on both sides.
$ \frac{2535}{65} \geq \frac{65}{65}x$
$ 39 \geq x$
or we can also write:
$ x \leq 39$
Which is our solution.