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3 years ago

Please answer right ill give brainliest

Mathematics

2 answers:

PIT_PIT [208]3 years ago

6 0

Answer:

70 dollars

Step-by-step explanation:

Each number is increasing by 4.

Sunny_sXe [5.5K]3 years ago

3 0

Answer:

$70

Step-by-step explanation:

When looking at the chart, you can see that with each chore she does, she earns $4. Knowing this, we can subtract $4 from the amount she had when she did one chore, that being $74. 74-4=70.

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Need help ASAP

xz_007 [3.2K]

Answer:

Alternate Interior angles! ? = 50 :)

Step-by-step explanation:

They are both interior, and they are alternate, so the type of angle pair is an alternate interior angles pair!

Relationship: They are congruent to each other!

They are also both equal! :)

7 0

3 years ago

A tank contains 60 kg of salt and 1000 L of water. Pure water enters a tank at the rate 6 L/min. The solution is mixed and drain

MissTica

Answer:

(a) 60 kg; (b) 21.6 kg; (c) 0 kg/L

Step-by-step explanation:

(a) Initial amount of salt in tank

The tank initially contains 60 kg of salt.

(b) Amount of salt after 4.5 h

$\text{Let A = mass of salt after t min}\\\text{and }r_{i} = \text{rate of salt coming into tank}\\\text{and }r_{0} =\text{rate of salt going out of tank}$

(i) Set up an expression for the rate of change of salt concentration.

$\dfrac{\text{d}A}{\text{d}t} = r_{i} - r_{o}\\\\\text{The fresh water is entering with no salt, so}\\ r_{i} = 0\\r_{o} = \dfrac{\text{3 L}}{\text{1 min}} \times \dfrac {A\text{ kg}}{\text{1000 L}} =\dfrac{3A}{1000}\text{ kg/min}\\\\\dfrac{\text{d}A}{\text{d}t} = -0.003A \text{ kg/min}$

(ii) Integrate the expression

$\dfrac{\text{d}A}{\text{d}t} = -0.003A\\\\\dfrac{\text{d}A}{A} = -0.003\text{d}t\\\\\int \dfrac{\text{d}A}{A} = -\int 0.003\text{d}t\\\\\ln A = -0.003t + C$

(iii) Find the constant of integration

$\ln A = -0.003t + C\\\text{At t = 0, A = 60 kg/1000 L = 0.060 kg/L} \\\ln (0.060) = -0.003\times0 + C\\C = \ln(0.060)$

(iv) Solve for A as a function of time.

$\text{The integrated rate expression is}\\\ln A = -0.003t + \ln(0.060)\\\text{Solve for } A\\A = 0.060e^{-0.003t}$

(v) Calculate the amount of salt after 4.5 h

a. Convert hours to minutes

$\text{Time} = \text{4.5 h} \times \dfrac{\text{60 min}}{\text{1h}} = \text{270 min}$

b.Calculate the concentration

$A = 0.060e^{-0.003t} = 0.060e^{-0.003\times270} = 0.060e^{-0.81} = 0.060 \times 0.445 = \text{0.0267 kg/L}$

c. Calculate the volume

The tank has been filling at 6 L/min and draining at 3 L/min, so it is filling at a net rate of 3 L/min.

The volume added in 4.5 h is

$\text{Volume added} = \text{270 min} \times \dfrac{\text{3 L}}{\text{1 min}} = \text{810 L}$

Total volume in tank = 1000 L + 810 L = 1810 L

d. Calculate the mass of salt in the tank

$\text{Mass of salt in tank } = \text{1810 L} \times \dfrac{\text{0.0267 kg}}{\text{1 L}} = \textbf{21.6 kg}$

(c) Concentration at infinite time

$\text{As t $\longrightarrow \, -\infty,\, e^{-\infty} \longrightarrow \, 0$, so A $\longrightarrow \, 0$.}$

This makes sense, because the salt is continuously being flushed out by the fresh water coming in.

The graph below shows how the concentration of salt varies with time.

3 0

3 years ago

Please answer all please

Firdavs [7]

Answer:

Step-by-step explanation:

The first parabola has vertex (-1, 0) and y-intercept (0, 1).

We plug these values into the given vertex form equation of a parabola:

y - k = a(x - h)^2 becomes

y - 0 = a(x + 1)^2

Next, we subst. the coordinates of the y-intercept (0, 1) into the above, obtaining:

1 = a(0 + 1)^2, and from this we know that a = 1. Thus, the equation of the first parabola is

y = (x + 1)^2

Second parabola: We follow essentially the same approach. Identify the vertex and the two horizontal intercepts. They are:

vertex: (1, 4)

x-intercepts: (-1, 0) and (3, 0)

Subbing these values into y - k = a(x - h)^2, we obtain:

0 - 4 = a(3 - 1)^2, or

-4 = a(2)². This yields a = -1.

Then the desired equation of the parabola is

y - 4 = -(x - 1)^2

7 0

3 years ago

3. The school library has 475 books.

galben [10]

Answer:

The school will have 535 books.

Step-by-step explanation:

12 books a month * 5 months = 60 additional books.

60 + 475 = 535 books.

7 0

3 years ago

Read 2 more answers

Find the equation of the line that passes through A and B

Alex777 [14]

Answer:

First we need to find the slope. This is (7 - 3) / (4 - 2) = 2. Since we know the slope, we can use point-slope form. I'm using the point (2, 3).

y - 3 = 2(x - 2)

y - 3 = 2x - 4

y = 2x - 1

4 0

3 years ago

Read 2 more answers