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What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)

Suppose y varies directly with x. write a direct variation equation that relates x and y. then find the value of y when x=12 y=7 when x=3

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.