All categories

3 years ago

Distribute 7 x (2+2x)

Mathematics

1 answer:

True [87]3 years ago

4 0

28 x because parenthesis first and you can’t do 2 + 2x so 7x times 2 is 14x and 7 times 2x is 14x

You might be interested in

Which two values of x are roots of the polynomial below? x^2-3x+5

Gemiola [76]

Given:

Polynomial $x^2-3x+5$

To find:

The values of x.

Solution:

$x^2-3x+5=0$

Quadratic equation formula:

$$x=\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}$

Here $a=1, b=-3, c=5$ .

Substitute the values in the formula, we get

$$x=\frac{-(-3) \pm \sqrt{(-3)^{2}-4 \cdot 1 \cdot 5}}{2 \cdot 1}$

$$x=\frac{3 \pm \sqrt{9-20}}{2}$

$$x=\frac{3 \pm \sqrt{-11}}{2}$

$$x=\frac{3 - \sqrt{-11}}{2} \ \text{and} \ x=\frac{3 + \sqrt{-11}}{2}$

Option E and option F are the roots of the polynomial.

The values of x are $x=\frac{3 - \sqrt{-11}}{2} \ \text{and} \ x=\frac{3 + \sqrt{-11}}{2}$ .

7 0

3 years ago

Half of a dome is called what?

Vesna [10]

Answer:

See I don't know the Answer but I Need points to ask question so Sorry

Step-by-step explanation:

3 0

3 years ago

Which interval contains a local minimum for the graphed function?

andreev551 [17]

Use photomath bc that app always helps

8 0

2 years ago

Read 2 more answers

A researcher wishes to estimate the average blood alcohol concentration (BAC) for drivers involved in fatal accidents who are f

Mnenie [13.5K]

Answer:

A 90% confidence interval for the mean BAC in fatal crashes in which the driver had a positive BAC is [0.143, 0.177] .

Step-by-step explanation:

We are given that a researcher randomly selects records from 60 such drivers in 2009 and determines the sample mean BAC to be 0.16 g/dL with a standard deviation of 0.080 g/dL.

Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean BAC = 0.16 g/dL

s = sample standard deviation = 0.080 g/dL

n = sample of drivers = 60

$\mu$ = population mean BAC in fatal crashes

<em>Here for constructing a 90% confidence interval we have used a One-sample t-test statistics because we don't know about population standard deviation. </em>

So, a 90% confidence interval for the population mean, $\mu$ is;

P(-1.672 < $t_5_9$ < 1.672) = 0.90 {As the critical value of t at 59 degrees of

freedom are -1.672 & 1.672 with P = 5%} P(-1.672 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 1.672) = 0.90

P( $-1.672 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $1.672 \times {\frac{s}{\sqrt{n} } }$ ) = 0.90

P( $\bar X-1.672 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+1.672 \times {\frac{s}{\sqrt{n} } }$ ) = 0.90

<u>90% confidence interval for</u> $\mu$ = [ $\bar X-1.672 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+1.672 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $0.16-1.672 \times {\frac{0.08}{\sqrt{60} } }$ , $0.16+1.672 \times {\frac{0.08}{\sqrt{60} } }$ ]

= [0.143, 0.177]

Therefore, a 90% confidence interval for the mean BAC in fatal crashes in which the driver had a positive BAC is [0.143, 0.177] .

7 0

3 years ago

I just need help on all of it

Inessa [10]

a
c
d
a
d
f
c
b
b
b
d
c
a
d
c
a
c
a-3+7/9=2.99
c
d
d

8 0

2 years ago