Answer:
15 rubber bands per day
Step-by-step explanation:
Let x be the 1st odd number, and x+2 the second odd consecutive number:
(x)(x + 2) = 6[((x) + (x+2)] -1
x² + 2x = 6(2x + 2) - 1
x² + 2x = 12x +12 - 1
And x² - 10x - 11=0
Solve this quadratic expression:
x' = [+10 +√(10²- 4.(1)(-11)]/2 and x" = [+10 -√(10²- 4.(1)(-11)]/2
x' = [10 + √144]/2 and x" = [10 - √64]/2
x' = (10+12)/2 and x" = (10-12)/2
x = 11 and x = -1
We have 2 solutions that satisfy the problem:
1st for x = 11, the numbers at 11 and 13
2nd for x = - 1 , the numbers are -1 and +1
If you plug each one in the original equation :(x)(x + 2) = 6[((x) + (x+2)] -1
you will find that both generates an equlity
Step-by-step explanation:
= -2(x - 5) + 4(9 + x)
= -2x + 10 + 36 + 4x
= (-2 + 4)x + 10 + 36
= 2x + 46
Answer:
24 Combinations Total
Step-by-step explanation:
METHOD 1 (no advanced math skills needed)
i. Number the friends: a, b, c, and d
ii. List all possible combinations...
- a b c d
- a b d c
- a c b d
- a c d b
- a d b c
- <u>a d c b</u>
- b a c d
- b a d c
- b c a d
- b c d a
- b d a c
- <u>b d c a</u>
- c a b d
- c a d b
- c b a d
- c b d a
- c d a b
- <u>c d b a</u>
- d a b c
- d a c b
- d b a c
- d b c a
- d c a b
- <u>d c b a</u>
To speed up the process instead of sitting here and listing 24 combinations, after two sections you can see that with friend "a" sitting all the way at the left there are six combinations and the same goes for friend "b". You can then multiply 6 (number of combinations with that friend <em>first</em>) and 4 (friends) to get 24.
METHOD 2
n! means the total number for permutations calculation (1 x 2 x ... until you reach <u><em>n</em></u><em> </em>) = 24
14 because he didn't gather 28 or more he gathered only 14
