Totally forgot how to do this, please help.

Pls help 25h²- 16t² factorise it

noname [10]

Answer:

(5h-4t)(5h+4t)

Step-by-step explanation:

25h² - 16t²

adding and subtracting 20ht from it (√25 and √16 = 5x4 = 20):

25h² + 20ht - 20ht -16t²

factor:

(5h-4t)(5h+4t)

8 0

2 years ago

Read 2 more answers

Assume that body masses of Goldfinch birds follow a normal distribution with standard deviation equal to 0.04 oz. An ornithologi

il63 [147K]

Answer:

The formula to generate 70% confidence interval is: $[\overline{x} - 0.013, \overline{x} + 0.013]$ , in which $\overline{x}$ is the sample mean.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.7}{2} = 0.15$

Now, we have to find z in the Z-table as such z has a p-value of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.15 = 0.85$ , so Z = 1.037.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

Assume that body masses of Goldfinch birds follow a normal distribution with standard deviation equal to 0.04 oz.

This means that $\sigma = 0.04$ .

Sample of 10 birds:

This means that $n = 10$ .

The margin of error is of:

$M = z\frac{\sigma}{\sqrt{n}}$

$M = 1.037\frac{0.04}{\sqrt{10}}$

$M = 0.013$

The lower end of the interval is the sample mean of $\overline{x}$ subtracted by M.

The upper end of the interval is the sample mean of $\overline{x}$ added to M.

Then, the formula to generate 70% confidence interval is: $[\overline{x} - 0.013, \overline{x} + 0.013]$ , in which $\overline{x}$ is the sample mean.

8 0

3 years ago

Si un buzo se sumerge 4 metros luego sube 2 metros y finalmente desciende 5 metros más, ¿a qué profundidad se encuentra al final

wolverine [178]

Así, concluimos que la posición final del buzo será 7 metros bajo la superficie del agua.

<h3 /><h3>¿a qué profundidad se encuentra al final de su recorrido?</h3>

Primero, vamos a definir la superficie del agua como el 0 metros.

Sí sabemos que primero el buzo se sumerge 4 metros, entonces en este punto la posición del buzo es:

P = 0m - 4m = -4m

Luego el buzo sube 2 metros, entonces la nueva posición será:

P = -4m + 2m = -2m

Finalmente, el buzo desciende otros 5 metros, entonces la posición final del buzo será:

P = -2m - 5m = -7m

Así, concluimos que la posición final del buzo será 7 metros bajo la superficie del agua.

Sí quieres aprender mas sobre posiciones:

brainly.com/question/21853903

#SPJ1

7 0

2 years ago

Math 9

Nata [24]

The answer is C (-3, -5), D(1,-5)

4 0

2 years ago

Read 2 more answers

I need help, please I have until 9 p.m. to finish it number 3 homework

sergeinik [125]

Answer: 1/3

<u>Step-by-step explanation:</u>

When adding or subtracting fractions, they must have the same denominator.

$\dfrac{5}{9}-\boxed{\dfrac{?}{?}}=\dfrac{12}{54}\\\\\\\dfrac{5}{9}\bigg(\dfrac{6}{6}\bigg)-\boxed{\dfrac{?}{?}}=\dfrac{12}{54}\\\\\\\dfrac{30}{54}-\boxed{\dfrac{?}{?}}=\dfrac{12}{54}\\\\\\\dfrac{30}{54}-\boxed{\dfrac{18}{54}}=\dfrac{12}{54}\\\\\\\text{Simplify}\quad \dfrac{18}{54}\div \dfrac{18}{18}\quad =\large\boxed{\dfrac{1}{3}}$

6 0

3 years ago