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3 years ago

Solve x2−5x=8 by completing the square. Round your answers to the nearest hundredth.

Mathematics

1 answer:

Bogdan [553]3 years ago

5 0

Answer:

$x = \dfrac{5}{2} \pm {\dfrac{\sqrt{57}}{2}$

Step-by-step explanation:

$x^2 - 5x = 8$

$x^2 - 5x + \dfrac{25}{4} = 8 + \dfrac{25}{4}$

$(x - \dfrac{5}{2})^2 = \dfrac{57}{4}$

$x - \dfrac{5}{2} = \pm \sqrt{\frac{57}{4}}$

$x = \dfrac{5}{2} \pm {\dfrac{\sqrt{57}}{2}$

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What is the value of |4 X -3 + 9| plzzz hurry

elixir [45]

Answer:

|4X + 6|

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

Can anyone help with this question pleasee

Vladimir [108]

Answer:

$y = 1$

Step-by-step explanation:

Given:

$a^{3y - 5} = \frac{1}{a^2}$

Apply the negative exponent rule

$a^{3y - 5} = a^{-2}$

The bases will cancel each other

$3y - 5 = -2$

$3y - 5 + 5 = -2 + 5$

$3y = 3$

$\frac{3y}{3} = \frac{3}{3}$

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7 0

3 years ago

If 79.5% of married couple households are both native and 13.2% are both foreign, then (a) what percentage of married couple hou

Zanzabum

Answer:

The correct solution is "7.3%".

Step-by-step explanation:

It seems that the given question is incomplete. Find below the attachment of the complete and appropriate query.

According to the question,

The total married couples are,

= 55,550,000

where,

Both native = 79.5%

Both foreign = 13.2%

Now,

The percentage of couple that is one native as well as one foreign will be:

= $100-79.5-13.2$

= $7.3$ (%)

7 0

3 years ago

The value of x varies directly with the value of y, and when x=20, y=18. What is the value of “k”, the constant of proportionali

stealth61 [152]

Answer:

In this case, y=30 and x=6, so 30=k*5<=> k=30/6=5.

Step-by-step explanation:

The constant of proportionality is the ratio between two directly proportional quantities. Two quantities are directly proportional when they increase and decrease at the same rate. The constant of proportionality k is given by k=y/x where y and x are two quantities that are directly proportional to each other.

8 0

3 years ago

A box contains 20 light box of which five or defective it for lightbulbs or pick from the box randomly what's the probability th

Snowcat [4.5K]

Answer:

Step-by-step explanation:

Given:-

- The box has n = 20 light-bulbs

- The number of defective bulbs, d = 5

Find:-

what's the probability that at most two of them are defective

Solution:-

- We will pick 2 bulbs randomly from the box. We need to find the probability that at-most 2 bulbs are defective.

- We will define random variable X : The number of defective bulbs picked.

Such that, P ( X ≤ 2 ) is required!

- We are to make a choice " selection " of no defective light bulb is picked from the 2 bulbs pulled out of the box.

- The number of ways we choose 2 bulbs such that none of them is defective, out of 20 available choose the one that are not defective i.e n = 20 - 5 = 15 and from these pick r = 2:

X = 0 , Number of choices = 15 C r = 15C2 = 105 ways

- The probability of selecting 2 non-defective bulbs:

P ( X = 0 ) = number of choices with no defective / Total choices

= 105 / 20C2 = 105 / 190

= 0.5526

- The number of ways we choose 2 bulbs such that one of them is defective, out of 20 available choose the one that are not defective i.e n = 20 - 5 = 15 and from these pick r = 1 and out of defective n = 5 choose r = 1 defective bulb:

X = 1 , Number of choices = 15 C 1 * 5 C 1 = 15*5 = 75 ways

- The probability of selecting 1 defective bulbs:

P ( X = 1 ) = number of choices with 1 defective / Total choices

= 75 / 20C2 = 75 / 190

= 0.3947

- The number of ways we choose 2 bulbs such that both of them are defective, out of 5 available defective bulbs choose r = 2 defective.

X = 2 , Number of choices = 5 C 2 = 10 ways

- The probability of selecting 2 defective bulbs:

P ( X = 2 ) = number of choices with 2 defective / Total choices

= 10 / 20C2 = 10 / 190

= 0.05263

- Hence,

P ( X ≤ 2 ) = P ( X =0 ) + P ( X = 1 ) + P (X =2)

= 0.5526 + 0.3947 + 0.05263

= 1

7 0

3 years ago