Solveit

i think you can t simplify it any more you can only multiply both by y you wil get (x-y)/(a+by) :/
 

i think: 

the first two can be any number so there is 36 possibilities on the third you are not allowed to repeat so yo you have 35 posibilities on the fourth one you can put any character so you have 36 and so on:

(36-2)/2=17

36^2*35^17*36^17 = 65902860965567704608604298035681925529600000000000000000

i think i understood it wrong that is why i get a very big number :)

Thanks CPhill :)

so the circumference of the circle is 56.55

\(Circumference=diameter \times \pi \\ d={c\over \pi} \\ d={56.55\over\pi}=18(aprox.)\)

you are welcome ! :)

40C2 it is in how many combinations you can choose 2 tickets but you need permitation here \(\frac{2}{40P2}=\frac{2}{1560}=\frac1{780}\)

How many ways can six people, A, B, C, D, E and F sit in a fow at a movie theater if either C, D or E has to be seated in the 1st seat?

So only C D E can seat on the first one wich is 3

if one of C D E sat on the first one he cannot sat on the second or third whch is 5

if two of them seated on the first and second one you left with 4 people

if three of them seated on the first , second and third one you left with 3 people

the 2 and 1 only the first seat is diffrent because on the first seat can only seat three persons

Answer: 3x5x4x3x2x1=360

Find four consecutive integers such that 3 times the sum of the first and third is 84 greater than the opposite of the second.

so it is your consecutive numbers:

\(\text{x , x+1 , x+2 , x+3}\)

3 times the sum of the first and third is 84 greater than the opposite of the second:

\(3\times(x+x+2)=-(x+1)+84 \\ 6x+6=-x+83 \\ 7x=77\\ x=11\)

so your numbers are 11, 12, 13, 14

∞*∞=∞

the probability of winning on the first ticket is \(2\over 40\)

the probability of wining on the second one is \({2-(1) \over 40-(1)}={1\over39}\)

the probabiity of winning on the both is \(\frac{2}{40}\times\frac{1}{39}=\frac{1}{780}=0.00128205\dots\)