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3 years ago

What the domain and range is for the function f(x) = x2 + 4x - 21.

Mathematics

1 answer:

prisoha [69]3 years ago

7 0

Answer:

Step-by-step explanation:

Please use " ^ " to denote exponentiation: f(x) = x^2 + 4x - 21.

This function has a graph which is a parabola that opens up.

Its vertex is found by completing the square:

x² + 4x + 4 - 4 - 21, or

(x + 2)² - 25

Comparing this to the standard equation

(x - h)² + k, we see that h = -2 and k = -25.

Thus, the vertex (and the minimum of this function) is (-2, -25).

Thus, the range is [-25, ∞ ). This being a polynomial function, it has no restrictions on the domain: the domain is (-∞, ∞ )

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Help me correct this plz

adelina 88 [10]

The answer will be D) 75

To find this it’s easiest to find how many animals there are per percent. So to find this you simply have to divide 30 (the number of cats) by 40 (the percent that makes up) to find the number of animals per percent.

30/40

.75

Then you multiply this by 100 to find how many animals there are total.

.75(100)

75

5 0

3 years ago

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(3.8 x 10 ^ -6) x (2.37 x 10 ^ -3)<br><br> Enter the answer in science notification

Black_prince [1.1K]

Multiply the coefficients and the powers of 10 with each other:

$(3.8 \times 10^{-6}) \times (2.37 \times 10^{-3}) = (3.8\times2.37) \times (10^{-6} \times10^{-3})$

The numeric part simply yields

$3.8\times2.37 = 9.006$

As for the powers of 10, you have to add the exponents, using the rule

$a^b \times a^c = a^{b+c}$

So, we have

$10^{-6} \times10^{-3} = 10^{-6-3} = 10^{-9}$

So, the final answer is

$9.006\times 10^{-9}$

7 0

3 years ago

Each student in a classroom has chosen either a green, red, or blue marble and written their initials on it. In addition, some o

scoundrel [369]

A. 2/5 B. 1/3 just like the other person said lol

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3 years ago

You plan to go skiing this weekend in Tennessee. The ski resort charges $18.50 per hour in addition to a $100 deposit to rent sk

Rina8888 [55]

Answer:

Part a) $y=18.50x+100$

Part b) The total cost is $\$220.25$

Part c) see the explanation

Step-by-step explanation:

Part a) Write a linear equation to represent this situation

Define the variables

Let

x ----> the number of hours

y ----> the total cost in dollars

we know that

The linear equation in slope intercept form is equal to

$y=mx+b$

where

m is the slope or the unit rate

b is the y-intercept or initial value (value of y when the value of x is equal to zero)

In this problem we have that

The unit rate or slope is equal to

$m=\$18.50\ per\ hour$

The y-intercept or initial value is equal to

$b=\$100$

substitute

$y=18.50x+100$

Part b) Use the equation to find the total cost to rent skis from 8:30 am to 3:00 pm

Remember that

3:00 pm=15:00

from 8:30 am to 3:00 pm, the total hours is equal to

15:00 -8:30=6:30=6.5 h

For x=6.5 h

substitute in the linear equation and solve for y

$y=18.50(6.5)+100\\y=\$220.25$

Part c) What does your answer mean in context of the problem?

we have that

y=220.25

That means -----> The total cost to rent skis for 6.5 hours is equal to $220.25

8 0

3 years ago

Mrs. Cleaver mixes 1.24 liters of red paint with 3 times as much blue paint to make purple paint. She pours the paint equally in

otez555 [7]

The amount of blue paint in each container is $\fbox{\begin\\\ 0.744 liters \end{minispace}}$ .

Further explanation:

The mixture mixed by Mrs. Cleaver contains 1.24 litres of red paint with 3 times blue paint to obtain purple paint.

So, the amount of blue paint is calculated as,

${3} \times {1.24}=3.72 \text { liters}$

Therefore, the total amount of paint mixture is the sum of blue paint and red paint.

$\fbox{\begin \\\begin{aligned} \text{Total paint}= 1.24+3.72\\=4.96 \text{ liters}\\\end{aligned}\\\end{minispace}}$

Now, as Mrs. Cleaver divides the paint mixture equally in 5 containers so the amount of paint in one container is calculated as,

$\boxed{\begin{aligned}\text{Amount of paint in one container}&= \dfrac{4.96}{5}\\ &=0.992 \text{ liters} \end {aligned}}$

Since amount of blue paint mixed is three times the red paint so the fraction of blue paint to the total paint is $\dfrac{3}{4}$ .

Now, as it is known that the fraction of blue paint to the total paint is $\dfrac{3}{4}$ and the amount of paint in a container is $0.992 \text{ liters}$ then the blue paint in one container is calculated as,

$\boxed{\begin{aligned}\text{Blue paint in one container} =\dfrac{3}{4} \times 0.992\\=0.248 \text{ liters}\end{aligned}}$

Thus, the amount of blue paint in each of the five containers is $\fbox{\begin\\\ 0.744 liters \end{minispace}}$ .

Learn more:

1. To solve one variable linear equation brainly.com/question/1682776

2. Linear equation application brainly.com/question/2479097

3. Composite functions brainly.com/question/2142762

Answer details

Grade: Middle school

Subject: Mathematics

Chapter: Mixtures and ratios

Keywords: mixture, paint, red paint, blue paint, Mrs. Cleaver, purple paint, fraction, each container, five containers, divides, times, equally divide, mixes, liters.

3 0

3 years ago

Read 2 more answers