Ask question

Ask question

All categories

3 years ago

8

Solve 2x2 + 12x − 14 = 0 by completing the square, options: A. 2(x + 6)2 = 26; x = −6 + square root 13, x = −6 − square root 13

B. 2(x + 6)2 = 20; x = −6 + square root 20, x = −6 − square root 20 C. 2(x + 3)2 = 32; x = 1, x = −7 D. 2(x + 3)2 = 32; x = 13, x = 19

2 answers:

musickatia [10]3 years ago

8 0

I just solved this one
anothe way is undistribute the 2 first and move -14 to side
2(x^2+6x)-14=0
comlete the squer inside and add negative
2(x^2+6x+9-9)-14=0
factor perfect square
2((x+3)^2-9)-14=0
distribute
2(x+3)^2-18-14=0
2(x+3)^2-32=0
add 32 both sides
2(x+3)^2=32
divide 2
(x+3)^2=16
sqrt both sides
x+3=+/-4
minus 3
x=-4-3 or 4-3
x=1 or -7

answer is C

bogdanovich [222]3 years ago

7 0

Answer:

the answer is c: 2(x + 3)2 = 32; x = 1, x = −7

Step-by-step explanation:

I took the test

You might be interested in

if 2 more students took the math test and both made a score of , what would the picture graph look like?

Sindrei [870]

I think it would be a dot graph

3 0

3 years ago

Read 2 more answers

A rectangle sand box has a length of 5 and 1/3 feet and a width of 3 and 3/4 feet. What is the perimeter?

Varvara68 [4.7K]

Answer:

Perimeter of rectangle = ⇒ $18\frac{1}{6}$ feet

Step-by-step explanation:

Given:

Length of a rectangular sand box = $5\frac{1}{3}\ feet$

Width of the box = $3\frac{3}{4}\ feet$

Perimeter of a rectangle = $2(l+w)$

where $l$ represents length of rectangle and $w$ represents width of the rectangle.

Substituting values given for length and width.

Perimeter of sand box = $2(5\frac{1}{3}+3\frac{3}{4})\ feet$

Simplifying by adding fractions:

⇒ $2(5+3+\frac{1}{3}+\frac{3}{4})\ feet$ (Adding whole numbers and fractions separately)

⇒ $2(8+\frac{1}{3}+\frac{3}{4})$ feet

Whole number 8 can be written as $\frac{8}{1}$

⇒ $2(\frac{8}{1}+\frac{1}{3}+\frac{3}{4})$ feet

To add fractions we take LCD for the denominators 3,4,1.

LCD for 3 and 4 = 12 as its the least common multiple of 3,4,1.

Making denominators =12 by multiplying numerator an denominator with the corresponding numbers

⇒ $2(\frac{8\times 12}{1\times 12}+\frac{1\times 4}{3\times 4}+\frac{3\times 3}{4\times 3})$ feet

⇒ $2(\frac{96}{12}+\frac{4}{12}+\frac{9}{12})$ feet

Then we simply add numerators.

⇒ $2(\frac{96+4+9}{12})$ feet

⇒ $2(\frac{109}{12})$ feet

⇒ $2\times \frac{109}{12}$ feet

⇒ $\frac{218}{12}$ feet

Writing fraction as a mixed number by dividing 218 by 12 and writing quotient as whole number and remainder as numerator with divisor as denominator.

⇒ $18\frac{2}{12}$ feet

Simplifying fractions to simplest form.

⇒ $18\frac{1}{6}$ feet

Perimeter =⇒ $18\frac{1}{6}$ feet (Answer)

5 0

3 years ago

What involves taking calculated risks

natali 33 [55]

Answer:

Calculated risks are risks that we can take even if we fail. Indeed, there are people willing to risk everything, and some even succeed, in doing so, but one has to see the overall picture in mind and only then make a decision

3 0

3 years ago

Find the domain of the following rational expression <br> f(x)=4x-8/5

Alchen [17]

4x is the correct answer

7 0

3 years ago

A personnel director in a particular state claims that the mean annual income is the same in one of the state's counties (Coun

Shalnov [3]

Answer:

a) The hypothesis that the mean annual income is the same could not be rejected. There is no enough evidence to claim they are different.

b) The critical values for this two-sided test are t=±1.711.

Step-by-step explanation:

<em>The question is incomplete:</em>

<em>(a) Identify the claim and state H0 and Ha. </em>

<em> Which is the correct claim below?</em>

<em>(b) Find the critical value(s) and identify the rejection region(s). </em>

<em> Enter the critical value(s) below.</em>

We have an hypothesis test on the difference of two means.

The null and alternative hypothesis are:

$H_0: \mu_a-\mu_b=0\\\\H_a: \mu_a-\mu_b\neq 0$

The claim of the alternative hypothesis is that the mean annual income is different in County A and County B.

The null hypothesis is that the mean annual income is equal in both counties.

The significance level is α=0.10.

The sample from County A has a mean of S40,400, a s.d. of $8,700 and a sample size of 18 residents.

The sample from County B has a mean of S39,200, a s.d. of $6,000 and a sample size of 8 residents.

The standard error of the difference of means is:

$\sigma_d=\sqrt{\frac{\sigma_a^2}{n_a}+\frac{\sigma_b^2}{n_b}}=\sqrt{\frac{8700^2}{18}+\frac{6000^2}{8}}=\sqrt{8705000}=2950$

The degrees of freedom are:

$df=n_a+n_b-2=18+8-2=24$

Then, the test statistic is:

$t=\frac{\Delta M-\Delta \mu}{\sigma_d} =\frac{(40,400-39,200)-0}{2950} =\frac{1200}{2950}=0.407$

For a statistic t=0.407, and df=24, the P-value is P=0.69. As the P-value is bigger than the significance level, the null hypothesis failed to be rejected.

If we would use the critial value approach, we would have to calculate the critical values for t, for df=24, two sided test and α=0.10.

The critical values, looking in a table, are t=1.711.

5 0

2 years ago