Simplify<br><br> (-28xy)divided by(-4)

Can anyone pls help with this ASAP!!! :((

MrRissso [65]

Answer: I believe your answer is C.

7 0

2 years ago

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Zmień jednostki prose o pomoc

Len [333]

Answer:

42300000

Step-by-step explanation:

Use known fact

$1\ km=1000\ m$

Consider 1 square kilometer:

$1\ km^2=1\ km\times 1\ km=1000\ m\times 1000\ m=1000000\ m^2$

So, to find the answer, you have to multiply given number of square kilometers by 1000000:

$42.3\ km^2=42.3\times 1000000\ m^2=42300000\ m^2$

4 0

3 years ago

Determine whether the equation is exact. If it is, then solve it. e Superscript t Baseline (7 y minus 3 t )dt plus (2 plus 7 e

umka21 [38]

Answer:

$F(t,y)=(2+7e^t)y+3(1-t)e^t +C$

Step-by-step explanation:

You have the following differential equation:

$e^t(7y-3t)dt+(2+7e^t)dy=0$

This equation can be written as:

$Mdt+Ndy=0$

where

$M=e^t(7y-3t)\\\\N=(2+7e^t)$

If the differential equation is exact, it is necessary the following:

$\frac{\partial M}{\partial y}=\frac{\partial N}{\partial t}$

Then, you evaluate the partial derivatives:

$\frac{\partial M}{\partial y}=\frac{\partial}{\partial t}e^t(7y-3t)\\\\\frac{\partial M}{\partial t}=7e^t\\\\\frac{\partial N}{\partial t}=\frac{\partial}{\partial t}(2+7e^t)\\\\\frac{\partial N}{\partial t}=7e^t\\\\\frac{\partial M}{\partial t} = \frac{\partial N}{\partial t}$

The partial derivatives are equal, then, the differential equation is exact.

In order to obtain the solution of the equation you first integrate M or N:

$F(t,y)=\int N \partial y = (2 +7e^t)y+g(t)$ (1)

Next, you derive the last equation respect to t:

$\frac{\partial F(t,y)}{\partial t}=7ye^t+g'(t)$

however, the last derivative must be equal to M. From there you can calculate g(t):

$\frac{\partial F(t,y)}{\partial t}=M=(7y-3t)e^t=7ye^t+g'(t)\\\\g'(t)=-3te^t\\\\g(t)=-3\int te^tdt=-3[te^t-\int e^tdt]=-3[te^t-e^t]$

Hence, by replacing g(t) in the expression (1) for F(t,y) you obtain:

$F(t,y)=(2+7e^t)y+3(1-t)e^t +C$

where C is the constant of integration

8 0

3 years ago

I need help with numbers 9and 10

AlekseyPX

For monthly membership, the cost must be less than $325. We can set up an inequality:-

100 + 30x < 325 where x = number of months of membership

Solving -

30x < 325-100 = 225

x < 225 / 30

x < 7.5 months

The answer is 7 months.

5 0

3 years ago

The average adult has approximately 1.25 gallons of blood. Blood donors typically donate 1 pint of blood. How many donations wou

viktelen [127]

10 pints.
We know that there are 8 pints in a gallon. We have one gallon so we already have 8 pints.
Then there is a .25 gallon, this is equivalent to one-fourth of a gallon. So 1/4 times 8 is 2.
8 + 2 is 10 pints.

7 0

3 years ago

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Simplify (-28xy)divided by(-4)