3x2 + 14x − 20 = (x + B)(3x − 4) What is B=

Find the total area for the regular pyramid.

hram777 [196]

Answer:

Option B

Step-by-step explanation:

Given is the hexagonal pyramid.

We know the radius of the base is same as its side.

Find the base area:

A = 3√3/2a²
A = 3√3/2*6² = 54√3

Given the height and radius, find the side of the lateral triangular faces:

$\sqrt{8^2+6^2} =\sqrt{100} =10$

Each of 6 triangles have sides 10, 10 and 6 units.

Find the area using heron's formula:

s = P/2 = (10*2 + 6)/2 = 13
s - a = s - b = 13 - 10 = 3
s - c = 13 - 6 = 7
$A = \sqrt{s(s-a)(s-b)(s-c)} =\sqrt{13*3*3*7} =3\sqrt{91}$

Total surface area:

$S = 6*3\sqrt{91}+54\sqrt{3} =18\sqrt{91}+54\sqrt{3}$

Correct choice is B

3 0

2 years ago

Square root of 5625

devlian [24]

Answer:

75

Step-by-step explanation:

75 × 75 = 5625

75² = 5625

6 0

3 years ago

Read 2 more answers

A researcher was interested in seeing how many names a class of 38 students could remember after playing a name game After playi

Andreas93 [3]

Answer:

Proportion of the students recalled more than 15 names is 91.77%.

Step-by-step explanation:

We are given that a researcher was interested in seeing how many names a class of 38 students could remember after playing a name game After playing the name game, the students were asked to recall as many first names of fellow students as possible.

The mean number of names recalled was 19.41 with a standard deviation of 3.17.

Let X = number of names recalled

SO, X ~ N( $\mu = 19.41,\sigma^{2} = 3.17^{2}$ )

The z-score probability distribution is given by ;

Z = $\frac{X-\mu}{\sigma} } }$ ~ N(0,1)

where, $\mu$ = mean number of names recalled = 19.41

$\sigma$ = standard deviation = 3.17

The Z-score measures how many standard deviations the measure is away from the mean. After finding the Z-score, we look at the z-score table and find the p-value (area) associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X.

Now, proportion of the students recalled more than 15 names is given by = P(X > 15 names)

P(X > 15) = P( $\frac{X-\mu}{{\sigma} } }$ > $\frac{15-19.41}{3.17} }$ ) = P(Z > -1.39)

= P(Z < 1.39) = 0.9177 {using z table}

Therefore, proportion of the students recalled more than 15 names is 91.77%.

4 0

3 years ago

-x + 2y = 3 2x – 3y = -6

s2008m [1.1K]

Answer:

x = -3

y = 0

Step-by-step explanation:

Given equations :- 

-x + 2y = 3 ....... ( i )

2x - 3y = -6 ....... ( ii )

From ( i ) 

-x + 2y = 3

-x = 3 - 2y

x = 2y - 3 ........ ( iii )

From ( ii ) 

2x - 3y = -6

2x = -6 + 3y

$x = \frac{ - 6 + 3y}{2}$

........ ( iv )

Equating ( iii ) and ( iv )

x = x

$2y - 3 = \frac{ - 6 + 3y}{2}$

4y - 6 = -6 + 3y

4y - 3y = -6 + 6

y = 0

Putting value of y in ( iii )

x = 2y - 3

x = 2 ( 0 ) - 3

x = -3

4 0

2 years ago

Which table identifies the one-sided and two-sided limits of function at x = 2?

Yuliya22 [10]

Answer:

Table 3

Step-by-step explanation:

Check table three;

$lim\:_{x\to \:2^-}\:f\left(x\right)=\:4$

$lim\:_{x\to \:2^+}\:f\left(x\right)=\:1$

Since the left hand limit $(lim\:_{x\to \:2^-}\:f\left(x\right))$ is not equal to the right hand limit $(lim\:_{x\to \:2^+}\:f\left(x\right))$ , the limit as x approaches to 2 does not exist.

Therefore "nonexistent" is true, and table 3 is the correct model of the limits of the function at x = 2

6 0

3 years ago