All categories

2 years ago

What is (2x + 7) - (2x - 4)

Mathematics

1 answer:

anyanavicka [17]2 years ago

8 0

Answer:

Step-by-step explanation:

(2x + 7) - (2x - 4)

2x + 7 - 2x + 4

7 + 4 = 11

You might be interested in

. In a town of 42,800 inhabitants, 48% are male. The rest are female. How many more females are there than males?

shutvik [7]

Answer:

1712

Step-by-step explanation:

100%-48%=52%

52-48=4

4% more.

42,800*0.04

1712

3 0

2 years ago

Read 2 more answers

F(x)=x^2 +10 Over which interval does f have a positive average rate of change?

EastWind [94]

Answer:

No x-intercept/Zero

Step-by-step explanation:

Substitute f (x)=0

Solve the equation

There is no x-intercept/zero

5 0

2 years ago

Read 2 more answers

Show that if X is a geometric random variable with parameter p, then

Lubov Fominskaja [6]

Answer:

$\sum_{k=1}^{\infty} \frac{p(1-p)^{k-1}}{k}=-\frac{p ln p}{1-p}$

Step-by-step explanation:

The geometric distribution represents "the number of failures before you get a success in a series of Bernoulli trials. This discrete probability distribution is represented by the probability density function:"

$P(X=x)=(1-p)^{x-1} p$

Let X the random variable that measures the number os trials until the first success, we know that X follows this distribution:

$X\sim Geo (1-p)$

In order to find the expected value E(1/X) we need to find this sum:

$E(X)=\sum_{k=1}^{\infty} \frac{p(1-p)^{k-1}}{k}$

Lets consider the following series:

$\sum_{k=1}^{\infty} b^{k-1}$

And let's assume that this series is a power series with b a number between (0,1). If we apply integration of this series we have this:

$\int_{0}^b \sum_{k=1}^{\infty} r^{k-1}=\sum_{k=1}^{\infty} \int_{0}^b r^{k-1} dt=\sum_{k=1}^{\infty} \frac{b^k}{k}$ (a)

On the last step we assume that $0\leq r\leq b$ and $\sum_{k=1}^{\infty} r^{k-1}=\frac{1}{1-r}$ , then the integral on the left part of equation (a) would be 1. And we have: