-4x+6y=-7<br> -13x-2y=-4 <br> Elimination or substitution

Help please help!! my grade is down

lisov135 [29]

plug in -2 for x

7*-2 -10 = -24

7 0

3 years ago

Given:

astraxan [27]

The answer is Vertical angles are equal.

5 0

3 years ago

Read 2 more answers

an inverted conical water tank with a height of 20 ft and a radius of 8 ft is drained through a hole in the vertex (bottom) at a

viktelen [127]

Answer:

the rate of change of the water depth when the water depth is 10 ft is; $\mathbf{\dfrac{dh}{dt} = \dfrac{-25}{100 \pi} \ \ ft/s}$

Step-by-step explanation:

Given that:

the inverted conical water tank with a height of 20 ft and a radius of 8 ft is drained through a hole in the vertex (bottom) at a rate of 4 ft^3/sec.

We are meant to find the rate of change of the water depth when the water depth is 10 ft.

The diagrammatic expression below clearly interprets the question.

From the image below, assuming h = the depth of the tank at a time t and r = radius of the cone shaped at a time t

Then the similar triangles ΔOCD and ΔOAB is as follows:

$\dfrac{h}{r}= \dfrac{20}{8}$ ( similar triangle property)

$\dfrac{h}{r}= \dfrac{5}{2}$

$\dfrac{h}{r}= 2.5$

h = 2.5r

$r = \dfrac{h}{2.5}$

The volume of the water in the tank is represented by the equation:

$V = \dfrac{1}{3} \pi r^2 h$

$V = \dfrac{1}{3} \pi (\dfrac{h^2}{6.25}) h$

$V = \dfrac{1}{18.75} \pi \ h^3$

The rate of change of the water depth is :

$\dfrac{dv}{dt}= \dfrac{\pi r^2}{6.25}\ \dfrac{dh}{dt}$

Since the water is drained through a hole in the vertex (bottom) at a rate of 4 ft^3/sec

Then,

$\dfrac{dv}{dt}= - 4 \ ft^3/sec$

Therefore,

$-4 = \dfrac{\pi r^2}{6.25}\ \dfrac{dh}{dt}$

the rate of change of the water at depth h = 10 ft is:

$-4 = \dfrac{ 100 \ \pi }{6.25}\ \dfrac{dh}{dt}$

$100 \pi \dfrac{dh}{dt} = -4 \times 6.25$

$100 \pi \dfrac{dh}{dt} = -25$

$\dfrac{dh}{dt} = \dfrac{-25}{100 \pi}$

Thus, the rate of change of the water depth when the water depth is 10 ft is; $\mathtt{\dfrac{dh}{dt} = \dfrac{-25}{100 \pi} \ \ ft/s}$

4 0

3 years ago

An angle measures 111.4° more than the measure of its supplementary angle. What is the measure of each angle?

fomenos

The measure of the supplementary angles are 34.3 and 145.7 degrees.

<h3>What are supplementary angles?</h3>

Supplementary angles are those angles that sum up to 180 degrees.

In other words, two angles are Supplementary when they add up to 180 degrees.

Therefore, the angles measures 111.4° more than the measure of it's supplementary angle.

Hence,

let

x = measure of the other angle

x + x + 111.4 = 180

2x + 111.4 = 180

subtract 111.4 from both sides

2x + 111.4 - 111.4 = 180 - 111.4

2x = 68.6

divide both sides by 2

x = 68.6 / 2

x = 34.3

Other angle = 34.3 + 111.4 = 145.7°

Therefore, the measure of the supplementary angles are 34.3 and 145.7 degrees.

learn more on supplementary angles here: brainly.com/question/15966137

#SPJ1

6 0

1 year ago

Which function listed below represents a greater rate of change, and what is the slope of the function?

Flauer [41]

Answer:

B

Step-by-step explanation:

i cant explan for this quasion but i am not understand this quation

8 0

2 years ago

-4x+6y=-7 -13x-2y=-4 Elimination or substitution