factor completely 9x4 + 12x3 + 21x2.

3(3x4 + 4x3 + 7x2)
3x(3x3 + 4x2 + 7x)
3x2(3x2 + 4x + 7)
prime

Which of the following transformations does not preserve congruence? * 5 points a. (x, y) → (y − 3, x − 3) b. (x, y) → (x + 5, y − 1) c. (x, y) → (y + 9, −x + 2) d. (x, y) → (3x + 1, 3y − 2)

Asays "we are both knaves" and b says nothing. exercises 24–31 relate to inhabitants of an island on which there are three kinds of people: knights who always tell the truth, knaves who always lie, and spies (called normals by smullyan [sm78]) who can either lie or tell the truth. you encounter three people, a, b, and c. you know one of these people is a knight, one is a knave, and one is a spy. each of the three people knows the type of person each of other two is. for each of these situations, if possible, determine whether there is a unique solution and determine who the knave, knight, and spy are. when there is no unique solution, list all possible solutions or state that there are no solutions. 24. a says "c is the knave," b says, "a is the knight," and c says "i am the spy."

Find the solution of each of the following.