You have to calculate how many ways you can select six things (r)
from a set of 9 things (n). (See attached formula).
9! / 6! * (3!) =
9*8*7 * 6! / 6! * 3! =
9*8*7 / 3! =
3 * 4 * 7 = 84 lineups
Solve for n by simplifying both sides of the equation, then isolating the variables.
n=54
Hope I helped
Answer:
I think 2. is A i dont know the other two
Step-by-step explanation:
Let w be the width of the deck. Then, using the total area, we get:
(9+2w)(18+2w)=400
4w²+54w-238=0
2w²+27w-119=0
(2w-7)(w+17)=0
w=-17 or 7/2
Using the positive value, we get a width of 3&1/2 ft. for the deck
☺☺☺☺