Help please!

(1 point) Let f(x) = 7 + 8x - x' . Find the open intervals on which f is increasing (decreasing). Then determine the x- coordinates of all relative maxima (minima). 1. f is increasing on the intervals 2. f is decreasing on the intervals 3. The relative maxima of f occur at x = 4. The relative minima of f occur at x = Notes: In the first two, your answer should either be a single interval, such as (0,1), a comma separated list of intervals, such as (-inf, 2), (3,4), or the word "none"