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2 years ago

Susan incorrectly factored the expression below. 12a − 15b + 6 3 (4a + 5b + 3)

Mathematics

1 answer:

hichkok12 [17]2 years ago

6 0

Answer:

3(4a−5b+2)

Step-by-step explanation:

The answer should have originally been 3(4a-5b+2)

3(4a+5b+3)= 12a+15b+9 which is incorrect.

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Evaluate using integration by parts

PolarNik [594]

Rather than carrying out IBP several times, let's establish a more general result. Let

$I(n)=\displaystyle\int x^ne^x\,\mathrm dx$

One round of IBP, setting

$u=x^n\implies\mathrm du=nx^{n-1}\,\mathrm dx$

$\mathrm dv=e^x\,\mathrm dx\implies v=e^x$

gives

$\displaystyle I(n)=x^ne^x-n\int x^{n-1}e^x\,\mathrm dx$

$I(n)=x^ne^x-nI(n-1)$

This is called a power-reduction formula. We could try solving for $I(n)$ explicitly, but no need. $n=5$ is small enough to just expand $I(5)$ as much as we need to.

$I(5)=x^5e^x-5I(4)$

$I(5)=x^5e^x-5(x^4e^x-4I(3))=(x-5)x^4e^x+20I(3)$

$I(5)=(x-5)x^4e^x+20(x^3e^x-3I(2))=(x^2-5x+20)x^3e^x-60I(2)$

$I(5)=(x^2-5x+20)x^3e^x-60(x^2e^x-2I(1))=(x^3-5x^2+20x-60)x^2e^x+120I(1)$

$I(5)=(x^3-5x^2+20x-60)x^2e^x+120(xe^x-I(0))$

Finally,

$I(0)=\displaystyle\int e^x\,\mathrm dx=e^x+C$

so we end up with

$I(5)=(x^4-5x^3+20x^2-60x+120)xe^x-120e^x+C$

$I(5)=(x^5-5x^4+20x^3-60x^2+120x-120)e^x+C$

and the antiderivative is

$\displaystyle\int2x^5e^x\,\mathrm dx=(2x^5-10x^4+40x^3-120x^2+240x-240)e^x+C$

8 0

2 years ago

What is 4,002 expressed in scientific notation?

Simora [160]

Answer:

4.002 x 10^3

Step-by-step explanation:

4 0

2 years ago

What is the distance between the lines y = 2x and y = 2x+5? Round your answer to the nearest tenth.

Ilia_Sergeevich [38]

The distance between both lines is 2.24 units

Step-by-step explanation:

There is no straight method to find the distance between two lines. The distance can be found out by finding a point on one line and then finding the distance of that point from the other line. The y-coordinate of point is obtained by putting any value of x in equation . The x and y combined give us the point.

Given

$y=2x\\Putting\ x=1\\y=2(1)\\y=2\\So, the\ point\ on\ y=2x\ is\ (1,2)$

We have to find the distance of this point from y=2x+5

$y=2x+5\\Subtracting\ y\ from\ both\ sides\\y-y=2x+5-y\\2x-y+5=0$

The formula for finding distance of a point (x,y) from a line is:

$d=\frac{|Ax+By+C|}{\sqrt{A^2+B^2}}$

A=2

B=-1

C=5

Putting the values in the formula

$d=\frac{|(2)(1)+(-1)(2)+5|}{\sqrt{(2)^2+(-1)^2}}\\d=\frac{|2-2+5|}{\sqrt{4+1}}\\d=\frac{|5|}{\sqrt{5}}\\d=\frac{5}{\sqrt{5}}\\d=2.236\ units$

Rounding off will give: 2.24 units

The distance between both lines is 2.24 units

Keywords: Equations of lines

Learn more about distance in lines at:

#LearnwithBrainly

7 0

2 years ago

Molly and henry went shopping for books molly bought 7 books for $42 and henry bought 8 book for $52 who got the better buy

Vesna [10]

Answer:

Molly

Step-by-step explanation:

because molly had

42 divided by 7

that gave her 6$ per book.

But Henry has

52 divided by 8

which is about 6.5.

That's why molly got the better deal.

3 0

3 years ago

What are two multiplication digits that equal to 3030

xz_007 [3.2K]

So x times y=3030
x and y=unknown
find the factors (factors of 6=2 and 3)
3030=2,3,5,101 so
two multiplication is
2 times 1515
3 times 1010
5 times 606
30 times 101
202 times 15
303 times 10
505 times 6

5 0

3 years ago