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3 years ago

Can some one plz help I'm comfuzzled

Mathematics

1 answer:

scZoUnD [109]3 years ago

5 0

14+ 13y - 13y = 20y - 13y -21 (taking away the smallest y value from both sides)

14 = 7y - 21

14 + 21 = 7y - 21 +21 (+21 on both sides to remove -21 if we do -14 then we will have nothing on other side)

35 = 7y

35/7 = 7y/7 (dividing 7 on both sides)

5 = y

answer is 100% correct no doubts. hope it helped you.

You might be interested in

In the given diagram, which of the following pairs of angles are alternate interior angles?

castortr0y [4]

Answer:

3 and 6

4 and 5

Step-by-step explanation:

Alternate interior angles are on the opposite sides of the transversal, t, and between the parallel lines, r and s

3 and 6 are alternate interior angles

4 and 5 are alternate interior angles

3 0

2 years ago

Read 2 more answers

Weight of a rock: In a geology course, students are learning to use a balance scale to accurately weigh rocks. One student plans

statuscvo [17]

Answer:

The student who weighted the rock 5 times has a 95% confidence interval of (25.2, 29.1) which is guaranteed to be more wider (less precise) than the other student who weighted the rock 20 times.

Step-by-step explanation:

What is Confidence Interval?

The confidence interval represents an interval that we can guarantee that the target variable will be within this interval for a given confidence level.

The confidence interval is given by

$CI = \bar{x} + t_{\alpha/2}(\frac{\sigma}{\sqrt{n} } ) \\$

Where $\bar{x}$ is the mean weight $\sigma$ is the standard deviation $t_{\alpha/2}$ is the critical value from t-table and n is the sample size.

The term $t_{\alpha/2}(\frac{\sigma}{\sqrt{n} } )$ is known as margin of error.

As the sample size is decreased the corresponding margin of error increases which results in wider confidence interval which means smaller precision.

The student who weighted the rock 5 times has a 95% confidence interval of (25.2, 29.1) which is guaranteed to be more wider (less precise) than the other student who weighted the rock 20 times.

We can say with 95% confidence that the true mean weight of the rock is within the interval of (25.2, 29.1).

7 0

3 years ago

Which expression is equivalent to n+n+n? A. 3^n B. 3n C. n^3 D. n+3

Irina18 [472]

Answer:

B. 3n

Step-by-step explanation:

n + n + n = 3n

------------------------------------------

3n = n + n + n

#IhopeThisHelp

5 0

2 years ago

Find dy/dx if f(x) = (x + 8)^3x.

vlabodo [156]

This is quite a complex problem. I wrote out a really nice solution but I can't work out how to put it on the website as the app is very poorly made. Still, I'll just have to type it all in...

Okay so you need to use a technique called logarithmic differentiation. It seems quite unnatural to start with but the result is very impressive.

Let y = (x+8)^(3x)

Take the natural log of both sides:

ln(y) = ln((x+8)^(3x))

By laws of logarithms, this can be rearranged:

ln(y) = 3xln(x+8)

Next, differentiate both sides. By implicit differentiation:

d/dx(ln(y)) = 1/y dy/dx

The right hand side is harder to differentiate. Using the substitution u = 3x and v = ln(x+8):

d/dx(3xln(x+8)) = d/dx(uv)

du/dx = 3

Finding dv/dx is harder, and involves the chain rule. Let a = x+ 8:

v = ln(a)
da/dx = 1
dv/da = 1/a

By chain rule:

dv/dx = dv/da * da/dx = 1/a = 1/(x+8)

Finally, use the product rule:

d/dx(uv) = u * dv/dx + v * du/dx = 3x/(x+8) + 3ln(x+8)

This overall produces the equation:

1/y * dy/dx = 3x/(x+8) + 3ln(x+8)

We want to solve for dy/dx, achievable by multiplying both sides by y:

dy/dx = y(3x/(x+8) + 3ln(x+8))

Since we know y = (x+8)^(3x):

dy/dx = ((x+8)^(3x))(3x/(x+8) + 3ln(x+8))

Neatening this up a bit, we factorise out 3/(x+8):

dy/dx = (3(x+8)^(3x-1))(x + (x+8)ln(x+8))

Well wasn't that a marathon? It's a nightmare typing that in, I hope you can follow all the steps.

I hope this helped you :)

8 0

3 years ago

Can someone please help me it’s urgent

Evgen [1.6K]

Answer:

8.5 in

Step-by-step explanation:

You are solving for the hypotenuse right? So you would use this formula:

c = square root a^2+b^2

the c is the hypotenuse (long side of a right triangle) and a will be 4 and b will be 7.5. substitute the numbers in, solve, and you get 8.5 inches!

x = square root 4^2 + 7.5^2

x = square root 16 + 56.25

x = square root 72.25

x = 8.5 inches

8 0

3 years ago