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2 years ago

Solve the following quadratic by completing the square.

Mathematics

1 answer:

lianna [129]2 years ago

4 0

Answer:

$x = -5 \pm \sqrt{26}$

Step-by-step explanation:

$x^2+10x-1=0\\\\\implies x^2+2\cdot 5 x +5^2-5^2-1=0\\\\\implies (x+5)^2-25-1=0\\\\\implies (x+5)^2 -26=0\\\\\implies (x+5)^2 = 26\\\\\implies x +5 = \pm\sqrt{26}\\\\\implies x = -5 \pm \sqrt{26}$

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9. Earth turns on its axis once every 24 h. How many hours does earth take to complete 2 1/4 turns

Dima020 [189]

Answer:

Step-by-step explanation:

24* 2.25= 54

(.25 is 1/4 in decimal form)

7 0

2 years ago

5x+7/2=3/2x-14 solve this

Alchen [17]

X=-2

You can also check by plugging -2 in for x. Here is a picture. Please notify me if I made an error!

3 0

3 years ago

-32x + 45 – 7 (2x – 9) = 101

Evgesh-ka [11]

Answer:

$x = \frac{7}{46}$

Step-by-step explanation:

-32x+45-7(2x-9)=101

parenthesis first

-32x+45-14x+63=101

just combine like terms

-46x+108=101

minus 108 both sides

-46x= -7

answer is x 7 over 46

5 0

3 years ago

Read 2 more answers

HELP I NEED HELP ASAP

Nady [450]

Answer:

Step-by-step explanation:

because the -2 is where the point is and the slope will start there so when you draw a line the line will pass by (0,-2)

5 0

3 years ago

Customers arrivals at a checkout counter in a department store per hour have a Poisson distribution with parameter λ = 7. Calcul

IgorLugansk [536]

Answer:

(1)14.9% (2) 2.96% (3) 97.04%

Step-by-step explanation:

Formula for Poisson distribution: $P(k) = \frac{\lambda^ke^{-k}}{k!}$ where k is a number of guests coming in at a particular hour period.

(1) We can substitute k = 7 and $\lambda = 7$ into the formula:

$P(k=7) = \frac{7^7e^{-7}}{7!}$

$P(k=7) = \frac{823543*0.000911882}{5040} = 0.149 = 14.9\%$

(2)To calculate the probability of maximum 2 customers, we can add up the probability of 0, 1, and 2 customers coming in at a random hours

$P(k\leq2) = P(k=0)+P(k=1)+P(k=2)$

$P(k\leq2) = \frac{7^0e^{-7}}{0!} + \frac{7^1e^{-7}}{1!} + \frac{7^2e^{-7}}{2!}$

$P(k \leq 2) = \frac{0.000911882}{1} + \frac{7*0.000911882}{1} + \frac{49*0.000911882}{2}$

$P(k\leq2) = 0.000911882+0.006383174+0.022341108 \approx 0.0296=2.96\%$

(3) The probability of having at least 3 customers arriving at a random hour would be the probability of having more than 2 customers, which is the invert of probability of having no more than 2 customers. Therefore:

$P(k\geq 3) = P(k>2) = 1 - P(k\leq2) = 1 - 0.0296 = 0.9704 = 97.04\%$

4 0

3 years ago