)in the 1980s, the population of pleasanton decreased by 10%. in the 1990s, its population increased
by 20%. how does the population of pleasanton at the end of the 1990s compare with its
population in 1980?

Look, when you want to do something like put it like x^2. x2 could mean x² or x₂. so to clear confusion, know the notation. to find the product multiply the x's and you get -8x and the y's and you get 6y. since it's all being multiplied it is just -8x6y, or answer a. although the better answer is -48xy(combining -8 and 6) because you should multiply constants whenever you can.