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3 years ago

x^2-8x+15=0 solve the equation by completing the square. Round your solutions to the nearest hundredth, if necessary.

Mathematics

1 answer:

zaharov [31]3 years ago

7 0

Answer:

x = 3, 5

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Equality Properties

Multiplication Property of Equality
Division Property of Equality
Addition Property of Equality
Subtract Property of Equality

Algebra I

Terms/Coefficients/Degrees
Standard Form: ax² + bx + c = 0
Multiple Roots
Factoring
Completing the Square: -b/(2a)

Step-by-step explanation:

Step 1: Define

x² - 8x + 15 = 0

Step 2: Solve for x

[Subtraction Property of Equality] Subtract 15 on both sides: x² - 8x = -15
Complete the Square [Addition Property of Equality]: x² - 8x + 16 = -15 + 16
[Complete the Square] Simplify: (x - 4)² = 1
[Equality Property] Square root both sides: x - 4 = ±1
[Addition Property of Equality] Add 4 on both sides: x = 4 ± 1
Evaluate: x = 3, 5

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Yea yea you know i need help my brains tiny thank you for everything and everyone helping

Darina [25.2K]

Answer: r=6

Step-by-step explanation:

Step 1: Substitute for the known variables

we know that the formula to find the volume of a cylinder is V= πr²h

π= 3.14

h= 12

r= ?

v=1,357

Plugging the numbers we know into the formula, we get:

1,357= 3.14xr²x12

1,357= 3.14x12xr² (because with the commutative property of multiplication you can multiply in any order)

1,357= 37.68 x r²

Step 2: Get the variable term (the letter term) on the left

37.68 x r²= 1,357

Now, divide by 37.68. (I know to divide because when you switch the 37.68x r² the other way around to r²x37.68, you are clearly multiplying and must do the inverse operation (opposite of multiplication; division) to solve the problem.

So,

r²= 1357÷37.68

r²= 36.0138004 ----> about 36.

r²= 36

This equation isn't over yet because we still have the exponent on the r. Whenever you see a letter squared (to the power 2) in an equation, the "inverse operation" is to take the square root of both sides. Look:

r²= 36

The square root of r² is just r, because r x r = r²

The square root of 36 is 6, because 6x6=36.

Now we have :

r= 6

Step 3: Check

Now we have all the variables. To check to make sure the radius is correct, "plug in"

V= π r²h

1,357= 3.14x6²x12

1,357= 3.14x36x12

1,357= 113.04x12

1,357= 1356.48

They said in the question that the volume is APPROXIMATLEY 1357, so I can just round 1356.48 --> 1356.5---> 1357. Now I am sure that the radius is 6.

Hope this helps :)) also brainliest would be appreciated :D

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2 years ago

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An event management company purchases a new van. The value of the van, x years after the purchase, is shown in the table. here i

Vlad1618 [11]

Answer:

Step-by-step explanation:

A is not right as we don't know the formula used so we cant say the x intercept

B is not right as the function is not liner

C The function is not liner

That leaves D!

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4 years ago

A fundraiser was held to split the profits between the 9 baseball players. How much money was raised if each player earned $326?

Black_prince [1.1K]

Answer:

Part 1

The number of baseball players that are to split the profits = 9 baseball payers

The amount of money each player earned = $326

Let x represent the total amount of money raised, and given that each baseball player received equal amount of the profits we have the following division equation;

$The \ division \ equation \ is , \dfrac{x}{9} = \$ \, 326$

Part 2

Solving for the variable, gives;

x = 9 × $ 326 = $2,934

The amount of profits from the fundraiser, x = $2,934

Part 3

The amount, A, each of the 9 players will earn from the profit of $2,934 raised in the fund raiser is given as follows;

A = $2,934/9 = $326

∴ The amount each of the 9 players will earn, A = $326, therefore the answer corresponds to the value in the question and is therefore, correct

Step-by-step explanation:

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3 years ago

Which situation represents a proportional relationship?

drek231 [11]

I believe it’s the last one.

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Twice a number is more than the sum of three times that number and 5

saw5 [17]

Answer:

31 = x

Step-by-step explanation:

First multiply out

2x + 10 = 3x - 21

Now collect terms

10 + 21 = 3x - 2x

Simplify

31 = x

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