All categories

3 years ago

What is the value of the expression 3x2 – 2y, if x - -2 and y = -4. 0 20 52 O-8 02

Mathematics

1 answer:

Dafna11 [192]3 years ago

6 0

Answer:

I think the answer is 20....I'm so sorry if that is wrong :[

You might be interested in

Write the point-slope form of an equation of the line through the points (-7, 7) and (4, 1).

seraphim [82]

Answer:

Choice B. $\displaystyle y - 7 = -\frac{6}{11} \, (x + 7)$ .

Step-by-step explanation:

Start by finding the slope of this line. Let $(x_1,\, y_1)$ and $(x_2,\, y_2)$ represent two distinct points on a line on a Cartesian Plane. (That is, $x_1 \ne x_2$ .) The slope of this line would be:

$\displaystyle \frac{y_2 - y_1}{x_2 - x_1}$ .

For the line in this question:

$x_1 = -7$ ,
$y_1 = 7$ ;

$x_2 = 4,$
$y_2 = 1$ .

Indeed, $x_1 \ne x_2$ . The slope of this line would thus be $\displaystyle \frac{1 - 7}{4 - (-7)}$ , which is equal to $\displaystyle -\frac{6}{11}$ .

On a Cartesian Plane, the point-slope form of a line that has a slope of $m$ and includes the point $(x_0,\, y_0)$ can be written as:

$y - y_0 = m\, (x - x_0)$ .

(Note the minus signs in this form.)

For the line in this question, $m = \displaystyle -\frac{6}{11}$ . There are two equivalent expressions for its point-slope form:

Using the first point, $y - 7 = \displaystyle -\frac{6}{11}\, (x - (-7))$ . This equation is equivalent to $y - 7 = \displaystyle -\frac{6}{11}\, (x + 7)$ .
Using the second point, $y - 1 = \displaystyle -\frac{6}{11}\, (x - 4)$ .

7 0

3 years ago

PLEASE HELP I WILL GIVE YOU BRAINLIEST

My name is Ann [436]

Answer: 200 boxes in 5 minutes

Step-by-step explanation:

Trust me :)

8 0

3 years ago

Read 2 more answers

One of the relatively uncommon instances in which researchers know the population standard deviation is in the case of the Intel

Phoenix [80]

Answer:

90% confidence interval for the mean IQ score in this community is [106.58 , 109.42].

Step-by-step explanation:

We are given that in general, the average IQ score in large, diverse populations is 100 and the standard deviation is 15.

Suppose that your sample of 300 members of your community gives you a mean IQ score of 108.

Firstly, the pivotal quantity for 90% confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample mean IQ score = 108

$\sigma$ = population standard deviation = 15

n = sample of members = 300

$\mu$ = population mean IQ score

Here for constructing 90% confidence interval we have used One-sample z test statistics because we know about population standard deviation.

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

P(-1.645 < N(0,1) < 1.645) = 0.90 {As the critical value of z at 5% level

of significance are -1.645 & 1.645}

P(-1.645 < $\frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n} } }$ < 1.645) = 0.90

P( $-1.645 \times {\frac{\sigma}{\sqrt{n} } }$ < ${\bar X -\mu}$ < $1.645 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.90

P( $\bar X-1.645 \times {\frac{\sigma}{\sqrt{n} } }$ < $\mu$ < $\bar X+1.645 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.90

90% confidence interval for $\mu$ = [ $\bar X-1.645 \times {\frac{\sigma}{\sqrt{n} } }$ , $\bar X+1.645 \times {\frac{\sigma}{\sqrt{n} } }$ ]

= [ $108-1.645 \times {\frac{15}{\sqrt{300} } }$ , $108+1.645 \times {\frac{15}{\sqrt{300} } }$ ]

= [106.58 , 109.42]

Therefore, we can be 90% confident that the mean IQ score in this community lies between 106.58 and 109.42.

8 0

3 years ago

How to find numbers between 0.22 and 0.23

Gelneren [198K]

Easy peasy
add zeros at end nd get
0.220
and
0.230
so some numbers are
0.21
0.22
0.23
0.24
0.25
0.26
0.27
0.28
0.29
you can even add more zeroes and go farther like
0.2209230840283482038428305790349

4 0

3 years ago

Read 2 more answers

Choose the graph below that correctly represents the equation 3x + 9y = −18. pls hurry

kykrilka [37]

Answer:

Step-by-step explanation:

Graph the line by first using slope and y- intercept

Slope=-1/3

y-intercept =-2

(0,-2)

(1,-7/3)

Then graph those two points and that graph is B

4 0

3 years ago

Read 2 more answers

What is the value of the expression 3x2 – 2y, if x - -2 and y = -4. 0 20 52 O-8 02​

What is the value of the expression 3x2 – 2y, if x - -2 and y = -4. 0 20 52 O-8 02