Which of the following is equivalent to 6x + 3y = 9 ?

Quick translate "x is 12 units from 20" into an equation. what are the values of x being described? if you can answer any of my other questions that'd be great too

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?

Which of the following can be used to explain a statement in a geometric proof?