Express in simplest form (5a^2-3a+8)+ ( -4a^2-1)+(15a +11)

Is the square root of 4 plus the square root of 16 rational?

How many grams the dog will eat in 3 days?

Jayne is studying urban planning and finds that her town is decreasing in population by 3% each year. the population of her town is changing by a constant rate. true or false?