Since this is a combination not a permutation problem, (order does not matter) you should use the "n choose k" formula.
C=n!/(k!(n-k)!) where C is the number of unique combinations, n equals the total number of possible choices and k equals the specific number of choices. In this case:
C=9!/(4!(9-4)!)
C=9!/(4!5!)
C=362880/(24*120)
C=362880/2880
C=126
So there are 126 unique ways to pick 4 people from a group of 9 people.
Answer:
what is the question
Step-by-step explanation:
Answer:
x = 1.27
y = 5.18
Step-by-step explanation:
to solve this system of equation by simultaneous equation we say that let
3x+y=9.............................. equation 1
-5x+2y=4 .......................... equation 2
from equation 1
3x+y=9.............................. equation 1
y = 9 -3x.............................. equation 3
substitute the value of y = 9 -3x into equation 2
-5x+2y=4 .......................... equation 2
-5x + 2( 9 -3x) = 4
-5x + 18 - 6x = 4
collect the like terms
18 - 4 = 6x + 5x
14 = 11x
divide both side by 11
14/11 = 11x/11
x = 14/11
x = 1.27
put the value of x = 1.27 into equation 3
y = 9 -3x.............................. equation 3
y = 9 - 3( 1.27)
y = 9 - 3.82
y = 5.18
<em>to check if you are correct put the value of x and y into either equation 1 or equation 2.</em>
<em>3x+y=9.............................. equation 1</em>
<em>3( 1.27) + 5.18 = 9</em>
<em>3.81 + 5.18 = 9</em>
<em>9 = 9</em>
this pic is of empty set I guess bro
