There are 8 marbles in a bag, each with a different color. How many different groups of 4 marbles can we select?

70

Step-by-step explanation:

8 choose 4

= (8!)/(4!*4!)

=(8*7*6*5)/(4*3*2*1)

=1680/24

=70

3 1/3 x 2 3/5 = 8 2/3

step-by-step explanation:

just multiply the first number by the second number to get your answer.

b) k’(6, 4); l’(3, 3)

step-by-step explanation:

a 270° clockwise rotation maps every point (x, y) to (y, -x). (it negates the x-coordinate and then switches it and the y-coordinate.)

this means the endpoints of the side congruent to kl, k' and l', would be mapped as:

k'(-4, 6)→(6, 4)

l'(-3, 3)→(3, 3)