How many sign changes are in the polynomial f(x) = 3x3 - 7x2 - 9x + 1

Pls if a cow has a mass of 9×10^2 kilograms, and a blue whale has a mass of 1.8×10^5 kilograms, which of these statements is true?

He weights of 2-pound bags of best dog food are approximately normally distributed with a given mean  and standard deviation  according to the empirical rule, what percentage of the bags will have weights within 3 standard deviations of the mean? 47.5%68%95%99.7%

Will give brainliest b. describe the function over each part of its domain. state whether it is constant, increasing, or decreasing, and state the slope over each part.