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2 years ago

Solve x^2-8x-9=0 using completing the square (show the work)

Mathematics

1 answer:

Elden [556K]2 years ago

3 0

Answer: x=9,-1

Step-by-step explanation:

First, we are gonna start out with finding two numbers that multiply to equal -9 and add up to equal -8

Those numbers would be -9 & 1

-9+1=-8

-9x1=-9

Now we have

(x-9)(x+1)

x-9=0 x+1=0

+9 +9 -1 -1

x=9 x=-1

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Solve the following simultaneous linear equations.<br>2x + y = 5<br>4x – 3y = -10

Jet001 [13]

Answer:

(1/2,4)

Step-by-step explanation:

First, determine y in first equation: 2x+y=5 or y=5-2x

replace value of y determined in first equation (5-2x) into 2nd equation

4x-3(5-2x)=-10

4x-15+6x=10

10x=5

x=1/2

put value of x into either equation to solve for y so

2(1/2)+y=5

1+y=5

y=4

answer: x=1/2, y=4

check answer by substituting x and y into either equation:

4x-3y=-10

4(1/2)-3(4)=-10

2-12=-10

-10=-10

2x+y=5

2(1/2)+4=5

1+4=5

5=5

7 0

2 years ago

HEY GUYS HELP, ILL MARK YOU BRAINLY !

Serjik [45]

Y=40x+100 and the second question is y=1.69x

5 0

2 years ago

Which represents the solution set of an any quality 5X-9 greater than 21

Svet_ta [14]

Answer:

The last one

Step-by-step explanation:

5x<30

x<6

Because when you divide by pos+ number

the symbol cannot change.

6 0

2 years ago

In a binomial distribution, n = 8 and π=0.36. Find the probabilities of the following events. (Round your answers to 4 decimal p

skelet666 [1.2K]

Answer:

$\mathbf{P(X=5) =0.0888}$

P(x ≤ 5 ) = 0.9707

P ( x ≥ 6) = 0.0293

Step-by-step explanation:

The probability of a binomial mass distribution can be expressed with the formula:

$\mathtt{P(X=x) =(^{n}_{x} ) \ \pi^x \ (1-\pi)^{n-x}}$

$\mathtt{P(X=x) =(\dfrac{n!}{x!(n-x)!} ) \ \pi^x \ (1-\pi)^{n-x}}$

where;

n = 8 and π = 0.36

For x = 5

The probability $\mathtt{P(X=5) =(\dfrac{8!}{5!(8-5)!} ) \ 0.36^5 \ (1-0.36)^{8-5}}$

$\mathtt{P(X=5) =(\dfrac{8!}{5!(3)!} ) \ 0.36^5 \ (0.64)^{3}}$

$\mathtt{P(X=5) =(\dfrac{8 \times 7 \times 6 \times 5!}{5!(3)!} ) \times \ 0.0060466 \ \times 0.262144}$

$\mathtt{P(X=5) =(\dfrac{8 \times 7 \times 6 }{3 \times 2 \times 1} ) \times \ 0.0060466 \ \times 0.262144}$

$\mathtt{P(X=5) =({8 \times 7 } ) \times \ 0.0060466 \ \times 0.262144}$

$\mathtt{P(X=5) =0.0887645}$

$\mathbf{P(X=5) =0.0888}$ to 4 decimal places

b. x ≤ 5

The probability of P ( x ≤ 5) $\mathtt{P(x \leq 5) = P(x = 0)+ P(x = 1)+ P(x = 2)+ P(x = 3)+ P(x = 4)+ P(x = 5})$

${P(x \leq 5) = ( \dfrac{8!}{0!(8!)} \times (0.36)^0 \times (1-0.36)^8 \ ) + \dfrac{8!}{1!(7!)} \times (0.36)^1 \times (1-0.36)^7 \ +$ $\dfrac{8!}{2!(6!)} \times (0.36)^2 \times (1-0.36)^6 \ + \dfrac{8!}{3!(5!)} \times (0.36)^3 \times (1-0.36)^5 + \dfrac{8!}{4!(4!)} \times (0.36)^4 \times (1-0.36)^4 \ + \dfrac{8!}{5!(3!)} \times (0.36)^5 \times (1-0.36)^3 \ )$

P(x ≤ 5 ) = 0.0281+0.1267+0.2494+0.2805+0.1972+0.0888

P(x ≤ 5 ) = 0.9707

c. x ≥ 6

The probability of P ( x ≥ 6) = 1 - P( x ≤ 5 )

P ( x ≥ 6) = 1 - 0.9707

P ( x ≥ 6) = 0.0293

4 0

2 years ago

The ______________ of a sample statistic is the probability distribution of the population of all possible values of the sample

enot [183]

Answer:

Sampling distribution

Step-by-step explanation:

The sampling distribution of a sample statistic is the probability distribution of the population of all possible values of the sample statistic.

4 0

2 years ago