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3 years ago

What is the solution to the system of equations? 5x-3y=-9 2x-5y=4 (_,_)

1 answer:

4 0

$\left \{ {{5x-3y=-9\ \ | *(-2)} \atop {2x-5y=4\ \ | *5}} \right. \\\\ \left \{ {{-10x+6y=18} \atop {10x-25y=20}} \right. \\\\+---\\addition\ method\\\\
-19y=38\ \ \ | divide\ by\ -19\\
y=-2\\\\2x=4+5y\ \ \ | divide\ by\ 2\\\\
x=\frac{4+5y}{2}=\frac{4+5*(-2)}{2}=\frac{4-10}{2}=\frac{-6}{2}=-3\\\\Solution:\\ \left \{ {{y=-2} \atop {x=-3}} \right.$

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What is 13 divided by 5/8

Norma-Jean [14]

20.8 hope this helps :D

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3 years ago

Read 2 more answers

Plsss help ill give brainiest

Elena L [17]

To solve this problem, we have to use the area of both gauze or the dimensions on each gauze and compare them. we can see that the sheets are not similar as they have different areas.

<h3>Area of Rectangle</h3>

The area of a rectangle is given as the product between the length and it's width.

Data;

Length = 9in
Area = 45in^2
width = ?
length 2 = 4in
width 2 = 3in

$area = length * width$

In the first gauze, the area is given as 45in^2 and we have value of the length. To find the width of the first gauze can be calculated as

$A = length * width\\width = \frac{area}{length} \\width = \frac{45}{9} \\width = 5in$

We can see that the width are not equal so is their length.

But if we would truly compare them, the accurate way to do that is by their area

The area of the second gauze is given by

$a = 3 * 4 = 12in^2$

From the above calculations, we can see that the sheets are not similar as they have different areas.

Learn more on area of a rectangle here;

brainly.com/question/25292087

3 0

1 year ago

Can someone help me answer this question asap

dsp73

The volume is 134.4 and surface area is 276.8 hope this helps ! ^_^ dnt forget to mark me brainiest

7 0

3 years ago

If -y-2x^3=Y^2 then find D^2y/dx^2 at the point (-1,-2) in simplest form

algol13

Answer:

$\frac{d^2y}{dx^2} = \frac{-4}{3}$

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Algebra I

Factoring

Calculus

Implicit Differentiation

The derivative of a constant is equal to 0

Basic Power Rule:

f(x) = cxⁿ
f’(x) = c·nxⁿ⁻¹

Product Rule: $\frac{d}{dx} [f(x)g(x)]=f'(x)g(x) + g'(x)f(x)$

Chain Rule: $\frac{d}{dx}[f(g(x))] =f'(g(x)) \cdot g'(x)$

Quotient Rule: $\frac{d}{dx} [\frac{f(x)}{g(x)} ]=\frac{g(x)f'(x)-g'(x)f(x)}{g^2(x)}$

Step-by-step explanation:

Step 1: Define

-y - 2x³ = y²

Rate of change of tangent line at point (-1, -2)

Step 2: Differentiate Pt. 1

Find 1st Derivative

Implicit Differentiation [Basic Power Rule]: $-y'-6x^2=2yy'$
[Algebra] Isolate y' terms: $-6x^2=2yy'+y'$
[Algebra] Factor y': $-6x^2=y'(2y+1)$
[Algebra] Isolate y': $\frac{-6x^2}{(2y+1)}=y'$
[Algebra] Rewrite: $y' = \frac{-6x^2}{(2y+1)}$

Step 3: Differentiate Pt. 2

Find 2nd Derivative

Differentiate [Quotient Rule/Basic Power Rule]: $y'' = \frac{-12x(2y+1)+6x^2(2y')}{(2y+1)^2}$
[Derivative] Simplify: $y'' = \frac{-24xy-12x+12x^2y'}{(2y+1)^2}$
[Derivative] Back-Substitute y': $y'' = \frac{-24xy-12x+12x^2(\frac{-6x^2}{2y+1} )}{(2y+1)^2}$
[Derivative] Simplify: $y'' = \frac{-24xy-12x-\frac{72x^4}{2y+1} }{(2y+1)^2}$

Step 4: Find Slope at Given Point

[Algebra] Substitute in x and y: $y''(-1,-2) = \frac{-24(-1)(-2)-12(-1)-\frac{72(-1)^4}{2(-2)+1} }{(2(-2)+1)^2}$
[Pre-Algebra] Exponents: $y''(-1,-2) = \frac{-24(-1)(-2)-12(-1)-\frac{72(1)}{2(-2)+1} }{(2(-2)+1)^2}$
[Pre-Algebra] Multiply: $y''(-1,-2) = \frac{-48+12-\frac{72}{-4+1} }{(-4+1)^2}$
[Pre-Algebra] Add: $y''(-1,-2) = \frac{-36-\frac{72}{-3} }{(-3)^2}$
[Pre-Algebra] Exponents: $y''(-1,-2) = \frac{-36-\frac{72}{-3} }{9}$
[Pre-Algebra] Divide: $y''(-1,-2) = \frac{-36+24 }{9}$
[Pre-Algebra] Add: $y''(-1,-2) = \frac{-12}{9}$
[Pre-Algebra] Simplify: $y''(-1,-2) = \frac{-4}{3}$