Help pls I no it’s simple but I don’t understand pls look at the pictures or image pls pls number 1 pls

What number should be added to both sides of the equation to complete this square? x^2-10x=7

Suppose that an airline uses a seat width of 16.516.5 in. assume men have hip breadths that are normally distributed with a mean of 14.414.4 in. and a standard deviation of 0.90.9 in. complete parts (a) through (c) below. (a) find the probability that if an individual man is randomly selected, his hip breadth will be greater than 16.516.5 in. the probability is nothing. (round to four decimal places as needed.)

Reduce fractions expressing probability to lowest terms. in 3,000 repetitions of an experiment, a random event occurred in 500 cases. the expected probability of this event is?