what is a good way to find the dominant term of f(x)=(7*5^x+2^2x+15)/(5^x+2^2x+1) when finding horizontal tangents

5. (16 points) Consider the function given by 7 . 5" + 223 + 15 f(c) = 5 4 22x + 1 (a) (2 points) Which of the following would be the most reasonable first step to compute lim f(I)? 1-400 (Select one) O We identify the dominant term, which is 53, and divide both numerator an denominator by it. We identify the dominant term, which is 227, and divide both numerator an denominator by it. Once we plug in a = co, we get , hence the limit does not exist. O Once we plug in a = co, we get ", hence the limit is equal to 1