Determine whether the polynomial is a difference of squares and if it is, factor it. y^2

What are the solutions to the equation (x + 2)^2 = 49?

Mekhanik [1.2K]

Answer:

X= 5, -9

Step-by-step explanation:

(X+2)² =49

Expand the bracket,

 (X+2) (X+2)= 49

Apply the distributive property;

X(X+2) +2 (X+2) =49

X²+2X+2X+4=49

X²+4X+4=49

Move 49 to the left side of the equation;

X²+4X+4-49=0

X²+4X-45=0

Apply Factorisation method;

Consider the form

a²+bx+c=0

Find two numbers whose sum is equal to b and whose product is equal to c. Comparing with our equation;

B =4 and C =45

We can use 9 and -5, this is because ;

9+(-5)=4 and 9*(-5)= 45.

Replace X +4X-45=0 with (X-5) (X+9)=0

Therefore;

X-5=0

X+9=0

Moving to the left side of the equation;

Therefore X= 5 and -9

8 0

2 years ago

Read 2 more answers

You start at (10, 1). You move down 1 unit and left 7 units. Where do you end?

solmaris [256]

Translation in right or left causes the x coordinate to change while translation in up or down causes the y coordinate to change.

Moving left or down causes the coordinates to be going negative.

Moving right or up causes the coordinates to be positive.

Original point (10, 1).

Down 1 unit:

(10, 1 - 1) = (10, 0)

Left 7 units:

(10 - 7, 0) = (3, 0)

You end at (3, 0)

5 0

3 years ago

How do you find magnitude of a vector

Otrada [13]

Draw a vector triangle. When you draw the horizontal and vertical components, you end up with a right triangle. The magnitude of the vector is equal to the hypotenuse of the triangle so you can use the Pythagorean theorem to calculate it. Rearrange the Pythagorean theorem to calculate the magnitude

6 0

3 years ago

EU (European Union) countries report that 46% of their labor force is female. The United Nations wants to determine if the perce

miss Akunina [59]

Answer:

b. We are 95% confident that between 35.5% and 44.3% of the persons in the U.S. labor force is female.

Step-by-step explanation:

1) Data given and notation

n=500 represent the random sample taken

X represent the number of females in the U.S. labor force

$\hat p=0.46$ estimated proportion of females in the U.S. labor force

$\alpha=0.05$ represent the significance level (no given, but is assumed)

z would represent the statistic

p= population proportion of females in the U.S. labor force

2) Confidence interval

The confidence interval would be given by this formula

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 95% confidence interval the value of $\alpha=1-0.95=0.05$ and $\alpha/2=0.025$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=1.96$

And replacing into the confidence interval formula we got:

$0.46 - 1.96 \sqrt{\frac{0.46(1-0.46)}{500}}=0.416$

$0.46 + 2.58 \sqrt{\frac{0.46(1-0.46)}{500}}=0.504$

On this case the calculated interval is not the given , but let's assume that the confidence interval is given by the statment: "United States Department of Labor find that 95% confidence interval for the proportion of females in the U.S. labor force is .357 to .443."

3) Correct interpretation

a. The margin of error for the true percentage of females in the U.S. labor force is between 35.7% and 44.3%.

False the confidence interval not conclude about the margin of error conclude about the true proportion.

b. We are 95% confident that between 35.5% and 44.3% of the persons in the U.S. labor force is female.

True, the statement report the confidence level and the limits for the margin of error.

c. The percentage of females in the U.S. labro force is between 35.7% and 44.3%.

False, The statement is not correct because not reports the confidence level.

d. All sample of size 500 will yield a percentage of females in the U.S. labor force that falls within 35.7% and 44.3%

False the confidence interval is for the population proportion not just for the samples of size 500

e. None of these.

False, we have an option that is true.

8 0

3 years ago

HELP DUE IN 10 MINS! Find the scale factor. Solve for x. Scale Factor=?? x=??

stepladder [879]

Answer:

Scale factor = 1/2 and x = 18

Step-by-step explanation:

Given:

ΔABC ~ ΔDEF
AB = 36. BC = 30
DE = x, EF = 15
m∠B = m∠E = 72°

Corresponding sides are:

AB and DE
BC and EF

Corresponding sides have same ratio:

AB/DE = BC/EF
36/x = 30/15
x = 36/2
x = 18

The scale factor is:

DE/AB = 36/18 = 1/2

4 0

3 years ago

Determine whether the polynomial is a difference of squares and if it is, factor it. y^2 – 196