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3 years ago

I NEED HELP PLEASE, THANKS! :)

Mathematics

2 answers:

Kaylis [27]3 years ago

8 0

Take a look at the attachment below. It proves that the inverse of matrix P does exists, as option c,

Hope that helps!

Vsevolod [243]3 years ago

3 0

Answer: C

Step-by-step explanation:

Given a b

c d

Multiply the reciprocal of the determinant by d -b

-c a

Determinant = ad - bc = 2(-3) - 4(1)

= -6 - 4

= -10

$-\dfrac{1}{10}\left[\begin{array}{cc}-3&-4\\-1&2\end{array}\right] \\\\\\\\=\left[\begin{array}{cc}\dfrac{-3}{-10}&\dfrac{-4}{-10}\\\\\dfrac{-1}{-10}&\dfrac{2}{-10}\end{array}\right]\\\\\\\\=\left[\begin{array}{cc}\dfrac{3}{10}&\dfrac{2}{5}\\\\\dfrac{1}{10}&-\dfrac{1}{5}\end{array}\right]$

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What is 2 3/5 minus 1 3/8 estimate the answer.

daser333 [38]

Find a common denominator first

2 24/40 - 1 15/40 = 1 9/40

it is already in simplest form so you can not reduce it

6 0

2 years ago

8+(14+6) FIND EASIER EXPLAIN WHY

alexandr1967 [171]

Hi there and welcome to Brainly!

The answer to 8+(14+6) = 28. The reason for this is you add what is in parenthesis first then you add the number outside of the parenthesis. This follows the PEMDAS rule which is called the order of operations. PEMDAS is an acronym which stands for Parenthesis, Exponents, Multiplication/Division, and Addition/Subtraction, this is the order you should follow when solving any problem.

If you have anymore questions please feel free to ask them.

Your friend, ASIAX

8 0

3 years ago

The population of a colony of mosquitoes obeys the law of uninhibited growth. If there are 1000 mosquitoes initially and there a

Anettt [7]

Answer:

1) The size of the colony after 4 days is 6553 mosquitoes

2) After $t = 4.9\ days$

Step-by-step explanation:

To answer this question you must use the growth formula

$N = N_0e ^ {kt}$

Where

$N_0$ is the initial population of mosquitoes = 1000

t is the time in days

k is the growth rate

N is the population according to the number of days

We know that when t = 1 and $N_0=1000$ then N = 1600

Then we use these values to find k.

$1600 = 1000e ^{k(1)}\\\\\frac{1600}{1000} = e ^ k\\\\ln(\frac{1600}{1000}) = k\\\\k = 0.47$

Now that we know k we can find the size of the colony after 4 days.

$N = 1000e ^ {0.47(4)}\\\\N = 6553\ mosquitoes$

To know how long it should take for the population to reach 10,000 mosquitoes we must do N = 10000 and solve for t.

$10000 = 1000e ^ {0.47t}\\\\10 = e ^ {0.47t}\\\\ln(10) = 0.47t\\\\t = \frac{ln(10)}{0.47}\\\\t = 4.9\ days$

6 0

2 years ago

PROBLEM #5

andrezito [222]

Answer:

12.5%

Step-by-step explanation:

80 - 70 = 10

10 / 80 = 0.125

Convert decimal to percent.

0.125 = 12.5%

5 0

3 years ago

Prove that u(n) is a group under the operation of multiplication modulo n.

katrin2010 [14]

Answer:

The answer is the proof so it is long.

The question doesn't define u(n), but it's not hard to guess.

Group G with operation ∘

For all a and b and c in G:

1) identity: e ∈ G, e∘a = a∘e = a,

2) inverse: a' ∈ G, a∘a' = a'∘a = e,

3) closed: a∘b ∈ G,

4) associative: (a∘b)∘c = a∘(b∘c),

5) (optional) commutative: a∘b = b∘a.

Define group u(n) for n prime is the set of integers 0 < i < n with operation multiplication modulo n.

If n isn't prime, we exclude from the group all integers which share factors with n.

Identity: e = 1. Clearly 1∘a = a∘1 = a. (a is already < n).

Closed: u(n) is closed for n prime. We must show that for all a, b ∈ u(n), the integer product ab is not divisible by n, so that ab ≢ 0 (mod n). Since n is prime, ab ≠ n. Since a < n, b < n, no factors of ab can equal prime n. (If n isn't prime, we already excluded from u(n) all integers sharing factors with n).

Inverse: for all a ∈ u(n), there is a' ∈ u(n) with a∘a' = 1. To find a', we apply Euclid's algorithm and write 1 as a linear combination of n and a. The coefficient of a is a' < n.

Associative and Commutative:

(a∘b)∘c = a∘(b∘c) because (ab)c = a(bc)

a∘b = b∘a because ab = ba.

5 0

2 years ago

Read 2 more answers