Prove each statement by contrapositive a. For every pair of real numbers r and y, if r + y is irrational, then is irrational or y is irrational
b. For every pair of integers z and y. if ry is even, then r is even or y is even.
c. For every pair of integers z and y, if z - y is odd, then r is odd or y is odd.
d. For every pair of real numbers r and y, if r + y 20,then >10 ory 10
e. For every pair of positive real numbers x and y, if xy >400, then > 20 ory>20 Feedback?

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 + 4x + 5 = 0

Consider a bag that contains 220 coins of which 6 are rare indian pennies. for the given pair of events a and b, complete parts (a) and (b) below. a: when one of the 220 coins is randomly selected, it is one of the 6 indian pennies. b: when another one of the 220 coins is randomly selected (with replacement), it is also one of the 6 indian pennies. a. determine whether events a and b are independent or dependent. b. find p(a and b), the probability that events a and b both occur.

The coordinates r(1, -3), s(3, -1) t(5, -7) form what type of polygon? a right triangle an acute triangle an equilateral triangle an obtuse triangle