Answer:
190 possibilities.
Step-by-step explanation:
The problem is called 20 choose 2, given by the formula for combinations
C(20,2) = 20! / (2! (20-2)!) = 190
alternatively, we can reason it this way:
there are 20 choices to choose a captain and 19 choices for an alternate captain for a total of 380 ways.
However, there are 20 choices to choose an alternate captain and 19 choices for a captain for a total of 380 ways.
Since we are essentially double counting every choice of the posts, we need to divide 380 by 2 to get 190 ways.
Answer:
a+b=6
a-b =4
______subtract
(a-a)+(b-(-b))=6-4
0+2b = 2
b= 1
put the value of b at any equation
a+1 =6
then a=6-1=5
a square+b square= 25+1= 26
Answer:
x = 10
y = 25
Step-by-step explanation:
if you add the equations as they are then the 'y-term' is eliminated:
60x = 600
x = 10
substitute x=10 to find value of 'y':
40(10) + 4y = 500
400 + 4y = 500
4y = 100
y = 25
Check:
20(10) - 4(25) should equal 100
200 - 100 = 100
100 = 100
