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2 years ago

What are the solutions of the equation (x + 2)2 – 2(x + 2) – 15 = 0? Use u substitution to solve.

Mathematics

1 answer:

Scrat [10]2 years ago

6 0

Answer:

Step-by-step explanation:

hello :

(x + 2)2 – 2(x + 2) – 15 = 0

let : t= x+2

t²-2t-15 =0

(t-5)(t+3)=0

t-5=0 or t+3=0

t=5 or t=-3

but : t =x+2

if : t=5 x+2 =5 so : x=3

if : t= -3 x+2 = -3 so : x= -5

conclusion two solutions : 3 , -5

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Likurg_2 [28]

Answer:

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3 years ago

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just olya [345]

Answer:

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Step-by-step explanation:

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2 years ago

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2 years ago

Which expression is equivalent to<br> x2 - 8x + 13 = 0

Mila [183]

Answer:

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Step-by-step explanation:

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2 years ago

Calculate the data value that corresponds to each of the following z-scores.

Fynjy0 [20]

Answer:

a) 90.1

b) $35.6

c) 3.0915 hours

Step-by-step explanation:

The z-score measures how many standard deviations a score X is above or below the mean.

It is given by the following formula:

$Z = \frac{X - \mu}{\sigma}$

In which $\mu$ is the mean and $\sigma$ is the standard deviaition.

In all three cases, we have to find X

a. Final exam scores: Allison’s z-score = 2.30, μ = 74, σ = 7.

$Z = \frac{X - \mu}{\sigma}$

$2.30 = \frac{X - 74}{7}$

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b. Weekly grocery bill: James’ z-score = –1.45, μ = $53, σ = $12.

$Z = \frac{X - \mu}{\sigma}$

$-1.45 = \frac{X - 53}{12}$

$X - 53 = -1.45*12$

$X = 35.6$

Mean and standard deviation in dollars, so the answer also in dollars.

c. Daily video game play time: Eric’s z-score = –0.79, μ = 4.00 hours, σ = 1.15 hours.

$Z = \frac{X - \mu}{\sigma}$

$-0.79 = \frac{X - 4}{1.15}$

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$X = 3.0915$

Mean and standard deviation in hours, answer in hours.

6 0

2 years ago