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3 years ago

From the sum of 3a^2-ab-2b^2 and 2a^2+5ab-3b^2 subtract a^2-3ab-4b^2

Mathematics

2 answers:

melamori03 [73]3 years ago

4 0

Answer:

4a^2 + ab - 9b^2

Step-by-step explanation:

First, perform the indicated addition:

3a^2-ab-2b^2

2a^2+5ab-3b^2

------------------------

5a^2 + 4ab - 5b^2

From this sum we subtract a^2 - 3ab - 4b^2:

5a^2 + 4ab - 5b^2

-(a^2 - 3ab - 4b^2

------------------------------

4a^2 + ab - 9b^2

Luden [163]3 years ago

3 0

4a^2+7ab-b^2

Step-by-step explanation:

Add the first two equations together:

3a^2-ab-2b^2

+ 2a^2+5ab-3b^2

---------------------------

5a^2+4ab-5b^2

Subtract that answer from the remaining trinomial:

5a^2+4ab-5b^2

- a^2-3ab-4b^2

--------------------------

4a^2+7ab-b^2

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$45.58 - e = $19.95<br><br> What is e? And to Check is it True or False?

Anettt [7]

We can change up the expression to find e.

45.58 - 19.95 = e.

25.63 is the result of this, so we can check:

45.58 - 25.63 = 19.95.

e = 25.63

6 0

3 years ago

Can someone help me on this

BartSMP [9]

Answer:

Step-by-step explanation:

5 0

3 years ago

Sally has a piece of cloth used 1/3 of a foot of the cloth to make a pillow cover in another 4/7 of a foot of the cloth to make

iren [92.7K]

Answer:

$\frac{23}{21} feets$

Step-by-step explanation:

Given.

Sally started with two feets of cloth.

Total cloth = $2 feets$

She used $\frac{1}{3}$ of a foot of the cloth to make a pillow cover.

And another $\frac{4}{7}$ of a foot of the cloth to make a table cloth.

She used total cloth to make a pillow cover and table cloth = $\frac{1}{3} +\frac{4}{7}$

$=\frac{7+12}{21} \\=\frac{19}{21}$

Total used cloth by Sally = $\frac{19}{21}$

The equation for remaining cloth

remaining cloth = total cloth - used cloth

remaining cloth $= 2 - \frac{19}{21}$

remaining cloth $= \frac{2\times 21-19}{21}$

remaining cloth $= \frac{42-19}{21}$

remaining cloth $= \frac{23}{21}$

Sally has remaining cloth = $\frac{23}{21}$ feets

8 0

3 years ago

A study was conducted to determine whether there were significant differences between medical students admitted through special

Mekhanik [1.2K]

Answer:

$P(X\geq 9)=P(X=9)+P(X=10)$

And using the probability mass function we got:

$P(X=9)=(10C9)(0.913)^9 (1-0.913)^{10-9}=0.383$

$P(X=10)=(10C10)(0.913)^{10} (1-0.913)^{10-10}=0.402$

And replacing we got:

$P(X \geq 9) = 0.383 +0.402= 0.785$

Step-by-step explanation:

Let X the random variable of interest "number of students graduated", on this case we now that:

$X \sim Binom(n=10, p=0.913)$

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

$nCx=\frac{n!}{(n-x)! x!}$

We want to find the following probability:

$P(X\geq 9)=P(X=9)+P(X=10)$

And using the probability mass function we got:

$P(X=9)=(10C9)(0.913)^9 (1-0.913)^{10-9}=0.383$

$P(X=10)=(10C10)(0.913)^{10} (1-0.913)^{10-10}=0.402$

And replacing we got:

$P(X \geq 9) = 0.383 +0.402= 0.785$

3 0

4 years ago

A tortoise takes 1 1/4 hours to walk 5/6 miles. At this rate, how long does it take her to walk 1 mile?

Illusion [34]

Answer:

I think it is 3/2

Step-by-step explanation:

1 1/4 ÷ 5/6

5/4 × 6/5 = 30/20= 3/2

3 0

2 years ago