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3 years ago

Which method is the most effective method to use to solve x^2+4x+3=0

Mathematics

2 answers:

lukranit [14]3 years ago

6 0

Answer:

Completing the square.

Step-by-step explanation:

since there is no "a" term and the bx term is even, completing the square is your best bet.

miss Akunina [59]3 years ago

4 0

For this case we have as a simpler method the factorization. We must find two numbers that multiplied as a result +3 and added as a result +4.

These numbers are:

3 and 1. $3 + 1 = 4\\\\3 * 1 = 3$

So, we have to:

$x ^2 + 4x + 3 =\\(x + 3) (x+1)$

Answer:

$(x + 3) (x + 1)$

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What is the volume of a cylinder with a diameter equal to 6 and height equal to 8? Let pi = 3.14.

Sindrei [870]

Volume of a cylinder is pi*(radius)^2* height. pi is 3.14 and radius is half of diameter which would be 3. height is 8. Thus volume of a cylinder in your case is pi*9*8 or 72*pi which is approximately 226.19

8 0

3 years ago

Completely factored form of xy^3 – x^3y?

Zolol [24]

Answer:

xy(y - x)(y + x)

Step-by-step explanation:

take out a common factor xy from both terms

= xy(y² - x²)

y² - x² is a difference of squares and factors in general as (y - x)(y + x)

Hence

xy³ - x³y = xy(x - y)(x + y)

8 0

3 years ago

5x-1/5=7/3 Find The LCD That would eliminate the fractions

photoshop1234 [79]

Answer:

$x=\frac{7}{15}$

Step-by-step explanation:

$5x-\frac{1}{5} =\frac{7}{3}$

$5x - \frac{3}{15} = \frac{35}{15}$

$5x - \frac{3}{15} + \frac{3}{15} = \frac{35}{15} + \frac{3}{15}$

$5x=\frac{35}{15}$

$\frac{5x}{5} } =\frac{\frac{35}{15}}{5}$

$x=\frac{7}{15}$

7 0

3 years ago

Let the abbreviation PSLT stand for the percent of the gross family income that goes into paying state and local taxes. Suppose

gavmur [86]

Answer:

Number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.

Step-by-step explanation:

We are given that one wants to estimate the mean PSLT for the population of all families in New York City with gross incomes in the range $35.000 to $40.000.

If sigma equals 2.0, we have to find that how many families should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5.

Here, we will use the concept of Margin of error as the statement "true mean PSLT within 0.5" represents the margin of error we want.

SO, Margin of error formula is given by;

Margin of error = $Z_(_\frac{\alpha}{2}_ ) \times \frac{\sigma}{\sqrt{n} }$

where, $\alpha$ = significance level = 10%

$\sigma$ = standard deviation = 2.0

n = number of families

Now, in the z table the critical value of x at 5% ( $\frac{0.10}{2} = 0.05$ ) level of significance is 1.645.

SO, Margin of error = $Z_(_\frac{\alpha}{2}_ ) \times \frac{\sigma}{\sqrt{n} }$

0.5 = $1.645 \times \frac{2}{\sqrt{n} }$

$\sqrt{n} =\frac{2\times 1.645 }{0.5}$

$\sqrt{n} =6.58$

n = $6.58^{2}$

= 43.3 ≈ 43

Therefore, number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.

4 0

4 years ago

Tyler sells 20 of his records (r) and has 74 left. Which equation best represents this scenario?

Anna71 [15]

Answer:

Equation: r-20=74

Step-by-step explanation:

So he started with 94. I got B

6 0

3 years ago