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3 years ago

Two step equations -5n+8=-7

Mathematics

2 answers:

Helen [10]3 years ago

4 0

-5n=-7-8
-5n=-15
N=-15/-5
N=3

garri49 [273]3 years ago

4 0

-5n=-7-8 5n=-15 N=-15/-5 N=3.

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Can you please help me thank you

shutvik [7]

As a fraction it’s 9/10 and a decimal is 0.9

3 0

3 years ago

PLEASE HELP!!! This is a trigonometry question. A conveyor is used to lift to a shredder. The most efficient operating angle of

s2008m [1.1K]

You can use the sin function to solve this.

Think of a triangle with the conveyor being the longest side (hypotenuse). The height (the vertical side) is H=17m. The angle of elevation is a=36.2. We are looking for length of the hypotenuse, L.

The sin is the ratio of height to hypotenuse: sin(36.2) = H/L = 17/L

Now solve for L:

L = 17/sin(36.2) = 17m/0.59 = 28.78m

The conveyor needs to be approx. 28.8m long to get close to the max. efficient angle.

8 0

3 years ago

What is the perimeter of a triangle whose sides are 4x, 3x+5, and 9-x?

Komok [63]

Answer:

if these expression represent side lengths, then you simply add those three expressions, and that's the perimeter.

Step-by-step explanation:

I explore this idea a bit. obviously x < 5 (because 5-x has to be positive.

2x-5 > 0 is a requirement, also, so x > 2.5 is required.

3 0

3 years ago

Derivative of<br><img src="https://tex.z-dn.net/?f=%20%5Cfrac%7B%20%7B3x%7D%5E%7B2%7D%20-%202x%20-%201%20%7D%7B%20%7Bx%7D%5E%7B2

Anastaziya [24]

Answer:

$\displaystyle \frac{dy}{dx} = \frac{2x + 2}{x^3}$

Step-by-step explanation:

we would like to figure out the derivative of the following:

$\displaystyle \frac{ { 3x }^{2} - 2x - 1 }{ {x}^{2} }$

to do so, let,

$\displaystyle y = \frac{ { 3x }^{2} - 2x - 1 }{ {x}^{2} }$

By simplifying we acquire:

$\displaystyle y = 3 - \frac{2}{x} - \frac{1}{ {x}^{2} }$

use law of exponent which yields:

$\displaystyle y = 3 - 2 {x}^{ - 1} - { {x}^{ - 2} }$

take derivative in both sides:

$\displaystyle \frac{dy}{dx} = \frac{d}{dx} (3 - 2 {x}^{ - 1} - { {x}^{ - 2} } )$

use sum derivation rule which yields:

$\rm\displaystyle \frac{dy}{dx} = \frac{d}{dx} 3 - \frac{d}{dx} 2 {x}^{ - 1} - \frac{d}{dx} {x}^{ - 2}$

By constant derivation we acquire:

$\rm\displaystyle \frac{dy}{dx} = 0 - \frac{d}{dx} 2 {x}^{ - 1} - \frac{d}{dx} {x}^{ - 2}$

use exponent rule of derivation which yields:

$\rm\displaystyle \frac{dy}{dx} = 0 - ( - 2 {x}^{ - 1 -1} ) - ( - 2 {x}^{ - 2 - 1} )$

simplify exponent:

$\rm\displaystyle \frac{dy}{dx} = 0 - ( - 2 {x}^{ -2} ) - ( - 2 {x}^{ - 3} )$

two negatives make positive so,

$\displaystyle \frac{dy}{dx} = 2 {x}^{ -2} + 2 {x}^{ - 3}$

<h3>further simplification if needed:</h3>

by law of exponent we acquire:

$\displaystyle \frac{dy}{dx} = \frac{2 }{x^2}+ \frac{2}{x^3}$

simplify addition:

$\displaystyle \frac{dy}{dx} = \frac{2x + 2}{x^3}$

and we are done!

5 0

3 years ago

NEED HELP!!!!!! Please thank you

chubhunter [2.5K]

Answer:

1. 39 km/hr

2. $235

3. 16

4. 7m+3 inches

Step-by-step explanation:

1. Original speed of car: x km

x+21=60

x=39

original speed: 39 km/hr

2. Amount that the freshman class raised: x

2x+85=555

2x=555-85=470

x=235

Amount that the freshman class raised: $235

3. Number: x

5x-9=71

5x=71+9=80

x=16

The number: 16

3m+5+4m-2

= 3m+4m+5-2

=7m+3 inches

7 0

3 years ago