Somebody could help me ? ..

Guys please help! In triangle CDE, the measure of angle C is 90 degrees, side CD is 15 and DE is 3 more than CE. Find the length

AURORKA [14]

You can calculate it using the law of cosines: c^2=a^2+b^2-2*a*b*cos(C)

your triangle is
CD=15=a
CE=?=b
DE=CE+3=b+3=c
and C=90°

-> insert those values, with c substituted with b+3 to remove c

c^2=a^2+b^2-2*a*b*cos(C)
(b+3)^2=15^2+b^2-2*15*b*cos(90)
cos(90)=0->
(b+3)^2=15^2+b^2
b^2+2*3*b+3^2=225+b^2
6b+9=225
6b=216
b=36=CE

DE=CE+3=36+3=39

4 0

4 years ago

What is the value of x?<br> 14-x=21

Dahasolnce [82]

14 - x = 21

First, subtract 14 from both sides. / Your problem should look like: -x = 21 - 14
Second, simplify 21 - 14 to get 7. / Your problem should look like: -x = 7
Third, multiply both sides by -1. / Your problem should look like: x = -7

Answer: x = -7

5 0

4 years ago

In a recent Super Bowl, a TV network predicted that 53 % of the audience would express an interest in seeing one of its forthcom

rjkz [21]

<h3>Answer: -0.196</h3>

======================================================

Explanation:

We're conducting a one proportion Z test.

The hypothesized population proportion is p = 0.53, which is not to be confused with the p-value (unfortunately statistics textbooks seem to overuse the letter 'p'). Luckily this problem is not asking for the p-value.

The sample population proportion is

phat = x/n = 41/79 = 0.518987 approximately

The standard error (SE) is

SE = sqrt(p*(1-p)/n)

SE = sqrt(0.53*(1-0.53)/79)

SE = 0.056153 approximately

Making the test statistic to be

z = (phat - p)/(SE)

z = (0.518987 - 0.53)/0.056153

z = -0.19612487311452

z = -0.196

Which is approximate and rounded to 3 decimal places.

3 0

4 years ago

Estimate the sum or difference.

dangina [55]

1) $\frac{4}{6}+\frac{1}{8}=\frac{19}{24}$

2) $\frac{2}{6}+\frac{7}{8}=\frac{29}{24}$

3) $\frac{5}{6}-\frac{3}{8}=\frac{11}{24}$

4) $\frac{4}{6}+\frac{3}{8}=\frac{25}{24}$

5) $\frac{7}{8}-\frac{5}{6}=\frac{1}{24}$

6) $\frac{1}{6}+\frac{7}{8}=\frac{25}{24}$

Step-by-step explanation:

In order to calculate the sum of two fractions, we first have to find the lowest common denominator of the two fractions, then multiply the numerator of each fraction by the ratio between the lowest common denominator and the original denominator, and then add/subtract the two new numerators.

1)

$\frac{4}{6}+\frac{1}{8}=$

Here the lowest common denominator between 6 and 8 is 24,

So we have to rewrite each fraction as having denominator 24: this means that we have to multiply both numerator and denominator of the 1st fraction by 4 (because 24/6=4), and both numerator and denominator of the 2nd fraction by 3 (because 24/8=3).

So the new numerators of the two fractions are:

$4\cdot 4 = 16\\1\cdot 3 = 3$

The expression then becomes:

$\frac{4}{6}+\frac{1}{8}=\frac{16}{24}+\frac{3}{24}=\frac{16+3}{24}=\frac{19}{24}$

2)

$\frac{2}{6}+\frac{7}{8}=$

Here the lowest common denominator between 6 and 8 is again 24,

so we have again to multiply both numerator and denominator of the 1st fraction by 4, and both numerator and denominator of the 2nd fraction by 3.

So the new numerators of the two fractions are:

$2\cdot 4 = 8\\7\cdot 3 = 21$

And we get:

$\frac{2}{6}+\frac{7}{8}=\frac{8}{24}+\frac{21}{24}=\frac{8+21}{24}=\frac{29}{24}$

3)

$\frac{5}{6}-\frac{3}{8}$

The denominators are the same, so the lowest common denominator is always 24. So we can adopt the same procedure, and new numerators are:

$5\cdot 4 = 20\\3\cdot 3 = 9$

And so:

$\frac{5}{6}-\frac{3}{8}=\frac{20}{24}-\frac{9}{24}=\frac{20-9}{24}=\frac{11}{24}$

4)

$\frac{4}{6}+\frac{3}{8}=$

Using the same lowest common denominator, 24, the new numerators are:

$4\cdot 4 = 16\\3\cdot 3 = 9$

And so we can rewrite the expression as

$\frac{4}{6}+\frac{3}{8}=\frac{16}{24}+\frac{9}{24}=\frac{16+9}{24}=\frac{25}{24}$

5)

$\frac{7}{8}-\frac{5}{6}=$

Again, the lowest common denominator is 24. This time the denominator of the 1st fraction is 8 while the denominator of the 2nd fraction is 6, so we have to multiply the numerator of the 1st fraction by 3 and the numerator of the 2nd fraction by 4.

We get:

$7\cdot 3 = 21\\5\cdot 4 = 20$