Discrete mathematics: show that if x and y are integers and both x*y and x + y are even, then both x and y are even.
(hint: use proof by cases and proof by contraposition)

10 points? me . its important ‼️‼️

Aladder that is 20ft long is leaning against the side of a building. if the angle formed between the ladder and the ground is 75 degrees how far is the bottom of the from the base of the building?

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?