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2 years ago

14

Solve systems by substitutions y=x + 10 y= -6x-18

1 answer:

lbvjy [14]2 years ago

8 0

x + 10 = - 6x - 18

7x = - 28

x = - 4

and y = - 4 + 10 = - 6

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-36.12 divided by -5 3/5

Nataliya [291]

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<em>-</em><em> </em><em>BRAINLIEST</em><em> answerer</em>

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2 years ago

Convert 15 m² to in². How many square inches are in 15 square meters?

Sati [7]

Answer:

23250

Step-by-step explanation:

23250 square inches are in 15 square meters.

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2 years ago

Find an equation of the circle whose diameter has endpoints (1,-4) and (-3,6).

MAVERICK [17]

Answer:

$(x+1)^2+(y-1)^2=58$

Step-by-step explanation:

To find the equation of this circle, we must know the center and the radius.

We can find the radius by dividing the value of the distance formula by 2 (since $r=\frac{d}{2}$ ):

$d=\sqrt{(-3-1)^2+(6-(-4))^2}=\sqrt{116}\\r=d/2=\frac{\sqrt{116}}{2}$

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$\frac{1+(-3)}{2}=-1$

$\frac{-4+6}{2}=1$

Then, we substitute these values into the equation of a circle:

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3 0

3 years ago

Oil is pumped continuously from a well at a rate proportional to the amount of oil left in the well. Initially there were millio

JulijaS [17]

Answer:

The amount of oil was decreasing at 69300 barrels, yearly

Step-by-step explanation:

Given

$Initial =1\ million$

$6\ years\ later = 500,000$

Required

At what rate did oil decrease when 600000 barrels remain

To do this, we make use of the following notations

t = Time

A = Amount left in the well

So:

$\frac{dA}{dt} = kA$

Where k represents the constant of proportionality

$\frac{dA}{dt} = kA$

Multiply both sides by dt/A

$\frac{dA}{dt} * \frac{dt}{A} = kA * \frac{dt}{A}$

$\frac{dA}{A} = k\ dt$

Integrate both sides

$\int\ {\frac{dA}{A} = \int\ {k\ dt}$

$ln\ A = kt + lnC$

Make A, the subject

$A = Ce^{kt}$

$t = 0\ when\ A =1\ million$ i.e. At initial

So, we have:

$A = Ce^{kt}$

$1000000 = Ce^{k*0}$

$1000000 = Ce^{0}$

$1000000 = C*1$

$1000000 = C$

$C =1000000$

Substitute $C =1000000$ in $A = Ce^{kt}$

$A = 1000000e^{kt}$

To solve for k;

$6\ years\ later = 500,000$

i.e.

$t = 6\ A = 500000$

So:

$500000= 1000000e^{k*6}$

Divide both sides by 1000000

$0.5= e^{k*6}$

Take natural logarithm (ln) of both sides

$ln(0.5) = ln(e^{k*6})$

$ln(0.5) = k*6$

Solve for k

$k = \frac{ln(0.5)}{6}$

$k = \frac{-0.693}{6}$

$k = -0.1155$

Recall that:

$\frac{dA}{dt} = kA$

Where

$\frac{dA}{dt}$ = Rate

So, when

$A = 600000$

The rate is:

$\frac{dA}{dt} = -0.1155 * 600000$

$\frac{dA}{dt} = -69300$

<em>Hence, the amount of oil was decreasing at 69300 barrels, yearly</em>

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2 years ago

What is 1,23456817653 + 3,236157885 = ? Please

Ilia_Sergeevich [38]

Answer:

It is

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6 0

2 years ago