Answer:
a. 64, 128, 256 (geometric)
b. 11, 13, 15 (arithmetic)
c. 53, 61, 69 (arithmetic)
Step-by-step explanation:
(a) Each term is twice the previous term. so it is geometric with a common ratio of 2
(b) The difference between each term is 2. So it is arithmetic with a common difference of 2
(c) The difference between each term is 8. So it is arithmetic with a common difference of 8
Divide the first equation by 2 and add the result to the second equation. This will eliminate x.
... (-4x -2y)/2 + (2x +4y) = (-12)/2 +(-12)
... 3y = -18 . . . . . collect terms
... y = -6 . . . . . . . divide by 3
Substitute this into either equation to find x. Let's use the second equation, where the coefficient of x is positive.
... 2x +4(-6) = -12
... 2x = 12 . . . . . . . . add 24
... x = 6 . . . . . . . . . . divide by 2
The solution is (x, y) = (6, -6).
hi,
You have to use a formula which is known as of binomial coefficient which is :
k among n is : C ( n /k) = n! / k! ( n-k)!
! = factorial
ex : 5 object among 8 is : C ( 8/5 ) = 8 ! / 5! * ( 8-5) !
As 8! = 8*7*6*5*4*3*2*1 = 40 320
As 5! = 5*4*3*2*1 = 120
as 3 ! = 3*2*1 = 6
then : 40 320 / 120 * 6
40 320 / 720 = 56
Conclusion : there is 56 way to select 5 object among 8 of them.
ps : you can also use Pascal Triangle to do such a thing.
Answer:
i think its 14. if not sorry
Step-by-step explanation:
again sorry if im wrong sorry