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2 years ago

3. Complete the square for 3x2 - 6x = 21. Help

Mathematics

1 answer:

PSYCHO15rus [73]2 years ago

7 0

Answer:

x=1+2√2 or x=1−2√2

Step-by-step explanation:

Let's solve your equation step-by-step.

3x2−6x=21

Step 1: Since the coefficient of 3x^2 is 3, divide both sides by 3.

3x2−6x

x2−2x=7

Step 2: The coefficient of -2x is -2. Let b=-2.

Then we need to add (b/2)^2=1 to both sides to complete the square.

Add 1 to both sides.

x2−2x+1=7+1

x2−2x+1=8

Step 3: Factor left side.

(x−1)2=8

Step 4: Take square root.

x−1=±√8

Step 5: Add 1 to both sides.

x−1+1=1±√8

x=1±√8

x=1+2√2 or x=1−2√2

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The volume of a sphere can be determined by the formula V = 4/3 πr^3, where r is the radius. What is the volume of a sphere with

allochka39001 [22]

Answer:

$V = \frac{99}{7} x^{9}y^{-6}$

Step-by-step explanation:

Given

$V = \frac{4}{3}\pi r^3$

Required

Find V when

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

Substitute $\frac{3}{2}x^3y^{-2$ for r in $V = \frac{4}{3}\pi r^3$

$V = \frac{4}{3}\pi * (\frac{3}{2}x^3y^{-2})^3$

Open bracket

$V = \frac{4}{3}\pi * \frac{3}{2}^3 * x^{3*3}y^{-2*3}$

$V = \frac{4}{3}\pi * \frac{27}{8} * x^{9}y^{-6}$

Simplify the fractions

$V = \pi * \frac{9}{2} * x^{9}y^{-6}$

Let

$\pi = \frac{22}{7}$

So:

$V = \frac{22}{7} * \frac{9}{2} * x^{9}y^{-6}$

$V = \frac{11}{7} * \frac{9}{1} * x^{9}y^{-6}$

$V = \frac{99}{7} * x^{9}y^{-6}$

$V = \frac{99}{7} x^{9}y^{-6}$

6 0

2 years ago

Kiran says, "I bought 2.5 pounds of red and yellow lentils. Both were $1.80 per pound. I spent a total of $4.05." Write a system

Dmitry_Shevchenko [17]

Answer:

The system of equations is given as:

x + y = 2.5 .... Equation 1

1.8x + 1.8y = 4.05....Equation 2

Step-by-step explanation:

Kiran says, "I bought 2.5 pounds of red and yellow lentils. Both were $1.80 per pound. I spent a total of $4.05

Let

x represent red lentils

y represent yellow lentils.

x + y = 2.5 .... Equation 1

x = 2.5 - y

$1.80 × x + $1.80 × y = $4.05

1.80x + 1.80y = 4.05....Equation 2

The system of equations is given as:

x + y = 2.5 .... Equation 1

1.8x + 1.8y = 4.05....Equation 2

6 0

2 years ago

Wats da distance between 13 and -5

levacccp [35]

You would add them together if it’s on a number line bc u have to go 5 to get to 0 then another 13 so 13+5=18

6 0

1 year ago

Read 2 more answers

What is 6 1/2 + 10? please tell me and explain for me to understand

ipn [44]

Answer:

33/2

Step-by-step explanation:

6 1/2 ---> 13/2

10 ---> 20/2

13/2 + 20/2 =

33/2

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Fed [463]

A short simple answer of 3 hours

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