Answer:
x ∈ {-a, -b}
Step-by-step explanation:
1/(a+b+x) = 1/a +1/b +1/x . . . . given
abx = bx(a+b+x) +ax(a+b+x) +ab(a+b+x) . . . . multiply by abx(a+b+x)
(a+b)x^2 +(a+b)^2x +ab(a+b) = 0 . . . . . subtract abx
x^2 + (a+b)x +ab = 0 . . . . . divide by (a+b)
This is a quadratic equation in x. It will have two solutions, as given by the quadratic formula.
x = (-(a+b) ±√((a+b)^2 -4(1)(ab))/(2(1)) = (-(a+b) ± |a -b|)/2
Without loss of generality, we can assume a ≥ b, so |a -b| ≥ 0. Then ...
x = (-a -b -a +b)/2 = -a
x = (-a -b +a -b)/2 = -b
There are two solutions: x ∈ {-a, -b}.
Answer:
100000 4-digit codes
Step-by-step explanation:
using the digits 0 dash 9, we want to pick 4 digits code.
The total number of digits available for us to pick from is 10(0 to 9 has 10 digits). We want to pick the 4 digits code and repetition is allowed. This is a case where we apply permutation with repetition. It is different when repetition is not allowed. It gives more possible outcomes than when repetition is not allowed. We will apply the formula, n^r
Where n is the total number of digits we want to choose from and it is equal to 10
r is the number of digits we can choose and it is equal to 4.
Number of possible 4 digit codes
= 10^4 = 100000
Subtract 430 and 512 and turn into a percent
82%
Than 430+512is942
Divide by 82%is11.487804
Skip a few times until u reach 11.48
Add 4+8 and then dvd:1 dvd to buy
So 4+8is12 plus 11 is 23 and one dvd it’s 24
So the answe is 24%
Your question is so blur i cant see
plzz send a nice pics
