I need help with finding the sum of (x^4 + 2x^3 - 7x - 9) + (x^5 - 2x^4 + 8x + 18) in standerd form my answer is x^5 - x^4 + 2x^3 + x^2 + 9
is this correct

Describe the end behavior of the function below. f(x)=(2/3)^x-2 a. as x increases, f(x) approaches infinity. b. as x decreases, f(x) approaches 2. c. as x increases, f(x) approaches -2. d. as x decreases, f(x) approaches negative infinity.