Please help me ^^ This is due tomorrow

Which property is illustrated by the following statement? if hxa rgi, then rgi hxa.

Mexico city, mexico, is the world's second largest metropolis and is also one of its fastest-growing cities with a projected growth rate of 3.2% per year. its population in 1991 was 20,899,000 people. use the formula p = 20.899e0.032t to predict its population p in millions with t equal to the number of years after 1991. what is the predicted population to the nearest thousand of mexico city for the year 2010?

How to write four times a number, minus 6,is equal to theee times the number+8 as an equqtion