Go on. Explain.

Was the United States under Trump not any longer

The level of economic illiteracy in America astounds me but doesn't Suprise me given our public education system.

he is a quick economics 101 lesson

In a large cooperation like Exxon the vast majority of costs are fixed (relatively Stable month to month) those costs have to be paid every month no matter what the cost of energy. so any increase or decrease in revenue has an oversized effect of profit margin.

think of it this way
If you make $3000 a month (your revenue) and your monthly bills equal 2700 a month (your fixed costs) you have $300 of disposable income (profit) if your boss gives you a $300 raise (a10 percent increase in revenue) your disposable income (profit) has gone from $300 to $600 a 100% increase.
On the other hand, if your boss cuts your salary (revenue) 5% ($150) your disposable income (profit) has decreased to $150 a 50% decrease

Since the revenue of a company like Exxon is largely related the price of energy, a small change in either direction can mean a big swing in the profit margin of the company overall.

I would also add Supply and demand is the root OF ALL ECONOMIS Biden by cutting oil production and pipelines reduced supply while at the same time the ending of the plandemic increased demand the price of oil and gas had to increase.