All categories

3 years ago

Explain why -4 is not a real number but -8 is two equations below of what they look like

Mathematics

1 answer:

Margarita [4]3 years ago

7 0

-4 isn't a real number because there is no square root of -4. However, there is a cube root of -8, because -2 * -2 * -2 = -8.

You might be interested in

Write an equation of the line with the given slope, m and y intercept (0,b) m=-6, b =-1/2 plss

Arlecino [84]

Recall that an equation in slope-intercept form is as follows:

$y=mx+b,$

where m is the slope of the line, and (0,b) is the y-intercept.

Substituting m=-6, and b=-1/2 we get:

$y=-6x+(-\frac{1}{2})\text{.}$

Simplifying the above result we get:

$y=-6x-\frac{1}{2}\text{.}$

Answer:

$y=-6x-\frac{1}{2}\text{.}$

5 0

1 year ago

Solve the system of equations. 10x+y=−20 y=2x2−4x−16 ( , ) and ( , )

Sladkaya [172]

I will go about solving this using the elimination method.

First, convert the equations.

10x + y = -20
4x + y = -12

Second, find the easiest variable to get rid of and get rid of it! (In this case, y) We will subtract to get rid of y.

6x = -8

Third, you want to solve the equation.

6x = -8 (divide by 6)
x = $-1 \frac{1}{3}$

Fourth, solve for y by inserting the answer for x into one of the equations.

10( $-1 \frac{1}{3}$ ) + y = -20
$-13 \frac{1}{3}$ + y = -20 (subtract $-13 \frac{1}{3}$ )
y = $-6 \frac{2}{3}$

The solution for this system of equations is ( $-1 \frac{1}{3}$ , $-6 \frac{2}{3}$ ).

7 0

3 years ago

Read 2 more answers

What dose this sign mean in math ( )

polet [3.4K]

Answer:

< Less Than and > Greater Than

This symbol < means less than, for example 2 < 4 means that 2 is less than 4. This symbol > means greater than, for example 4 > 2. ≤ ≥ These symbols mean 'less than or equal to' and 'greater than or equal to' and are commonly used in algebra. In computer applications <= and >= are used.

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

4. A random variable X has a mean of 10 and a standard deviation of 3. If 2 is added to each value of X, what will the new mean

Ede4ka [16]

Adding 2 to each value of the random variable $X$ makes a new random variable $X+2$ . Its mean would be

$E[X+2]=E[X]+E[2]=E[X]+2$

since expectation is linear, and the expected value of a constant is that constant. $E[X]$ is the mean of $X$ , so the new mean would be

$E[X+2]=10+2=12$

The variance of a random variable $X$ is

$V[X]=E[X^2]-E[X]^2$

so the variance of $X+2$ would be

$V[X+2]=E[(X+2)^2]-E[X+2]^2$

We already know $E[X+2]=12$ , so simplifying above, we get

$V[X+2]=E[X^2+4X+4]-12^2$

$V[X+2]=E[X^2]+4E[X]+4-12^2$

$V[X+2]=(V[X]+E[X]^2)+4E[X]-140$

Standard deviation is the square root of variance, so $V[X]=3^2=9$ .

$\implies V[X+2]=(9+10^2)+4(10)-140=9$

so the standard deviation remains unchanged at 3.

NB: More generally, the variance of $aX+b$ for $a,b\in\mathbb R$ is

$V[aX+b]=a^2V[X]+b^2V[1]$

but the variance of a constant is 0. In this case, $a=1$ , so we're left with $V[X+2]=V[X]$ , as expected.

5 0

3 years ago

Tom's's garden has 9 tomato plants, 5 pepper plants, 3 squash plants, and 6 pumpkin plants.

Marianna [84]

Answer:

Squash plant.

Step-by-step explanation:

I'm not sure how to explain, but if you divide 9 by 3, you get 3. There are 3 squash plants, so that's the answer. You could also write it as a ratio...

9:3

3:1

I'm not exactly sure how to explain the ratio part either, but I hope it helped at least a little bit...have an amazing day :3

6 0

3 years ago