Express the ratio of A's to N's in the word SAVANNAH, in simplest form

Rectangle A has side lengths measuring 4 inches and 9 inches. Rectangle B is similar to rectangle A but has side lengths three t

Bess [88]

The answer is c. 78 square inches.

- you take both 4 and 9, multiply them by 3 which would give you 12 and 27. then you add 27 twice and 12 twice, together and get 78.

8 0

3 years ago

Two bags contained 50 kilograms of sugar each. After 3 times as much sugar was taken from the first bag than from the second bag

erma4kov [3.2K]

20 kg remaining in bag 1.
40 kg remaining in bag 2.

8 0

3 years ago

How do you solve this using substitution method 17x+7y=20 Y=20x-42

Nutka1998 [239]

Answer:

17 x + 7 y = 20

y =20x - 42

17 x + 7(20x - 42) = 20

17x + 140x - 294 = 20

157 x = 20 + 294

157x ÷ 157 = 314 ÷ 157

x = 2

y = 20x - 42 

y = 20 (2) - 42

y = 40 - 42

y = -2

there for x = 2 and y = -2 is the solution 

4 0

3 years ago

What is 15/4 as a mixed number?

max2010maxim [7]

It would be: 15/4 = 3 3/4

In short, Your Answer would be 3 3/4

Hope this helps!

8 0

4 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

4 years ago