All categories

3 years ago

Solve the equation 7/z-1 = 9/z+4

Mathematics

1 answer:

algol [13]3 years ago

3 0

Answer:

z is equal to 18.5

Step-by-step explanation:

When an equation is in the format a/b = c/d, the quickest way to simplify it is to cross multiply. Each side is multiplied by the other sides denominator, eliminating the division:

$\frac{7}{z-1} = \frac{9}{z + 4}\\7(z + 4) = 9(z - 1)\\7z + 28 = 9z - 9\\7z - 9z = -9 - 28\\-2z = -37\\z = 37/2\\z = 18.5$

So z is equal to 18.5

You might be interested in

In a study of cell phone use and brain hemispheric dominance, an Internet survey was e-mailed to 2455 subjects randomly select

Genrish500 [490]

Answer: 0.355,0.405)

Step-by-step explanation:

Given : Significance level : $\alpha=1-0.99=0.01$

Number of subjects (n) = 2455

Number of surveys returned = 931

The probability of surveys get return will be :-

$p=\dfrac{931}{2455}=0.379226069246\approx0.38$

The confidence interval for proportion is given by :-

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

$0.38\pm z_{0.005}\times\sqrt{\dfrac{0.38(1-0.38)}{2455}}\\\\=0.38\pm(2.576)0.0098\\\approx0.38\pm0.025=(0.355,0.405)$

Hence, the 99% confidence interval for the proportion of returned surveys : (0.355,0.405)

5 0

3 years ago

This shape is made using three semicircles The smaller semicircle have diameters of 10cm Calculate the shaded area Take 3.142 an

CaHeK987 [17]

Answer:

The shaded area is 314.2 cm²

Step-by-step explanation:

Here we have the diameter, d₁ of the smaller semicircles as 10 cm

We note that the larger semicircle is subtended (bounded) by the two smaller semicircles;

1 shaded small semicircle and the other is blank

Therefore, the diameter, d₂ of the large semicircle = 10 + 10 = 20 cm

Also the area of the shaded figure consists of the removal of one small semicircle and the addition of the other semicircle to the area of the larger semicircle such that the area of the shaded figure is as follows

Shaded area of figure = π·d₂²/4 + π·d₁²/4 - π·d₁²/4 = π·d₂²/4 = π×20²/4 = 100×3.142 = 314.2 cm²

Shaded area = 314.2 cm².

6 0

3 years ago

Which set of parametric equations represents the following function? y=/x+3?

Darina [25.2K]

The given equation is:

$y= \sqrt{x+3}$

We need to find which set of parametric equations, result in the equation given above. The correct answer is option A.

$x=5t, y= \sqrt{5t+3}$

From first equation, we can write t =x/5. Using this value in second equation, we get:

$y= \sqrt{5( \frac{x}{5} )+3} \\ \\ 
y= \sqrt{x+3}$

Thus the set of equations in option A result in the given relation.
So, the answer to this question is option A

4 0

3 years ago

Read 2 more answers

How to do this and whats the answer

Vinvika [58]

Answer:

(b) 36 degrees.

Step-by-step explanation:

K is the center of the circle so triangle KMN is isosceles and m < KMN = m KNM = 26 degrees ( base angles are equal)

So m < LMK = m <LMN - m < KMN

= 98 - 26

= 72 degrees.

Now triangle LKM is also isosceles since K is the center of the circle so

m < LKM = 180 - 2* 72

= 180 - 144

= 36 degrees.

4 0

3 years ago

Howto solve for x in X+10=30

Alla [95]

Answer:

Step-by-step explanation:

x+10=30

x=30-10

x=20

<h2>HOPE IT HELPED </h2>

3 0

3 years ago

Read 2 more answers