X² – 38x+c what is the value of c

If you want to place an 8 ½ inch towel bar in the center of a door that is 25 ½ wide, how much space will be on each side of the towel bar?

Which expression is equivalent to 2x^2+7x+4?

The weight of full–grown tomatoes at a farm is modeled by a normal distribution with a standard deviation of 18.4 grams. the 95 percent confidence interval for the mean weight of the tomatoes is calculated using a sample of 100 tomatoes. what is the margin of error (half the width of the confidence interval)?