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3 years ago

11

How can you use the quadratic formula to complete a square?

2 answers:

Marina86 [1]3 years ago

6 0

It has become somewhat fashionable to have students derive the Quadratic Formula themselves; this is done by completing the square for the generic quadratic equation ax2 + bx + c = 0. While I can understand the impulse (showing students how the Formula was invented, and thereby providing a concrete example of the usefulness of abstract symbolic manipulation), the computations involved are often a bit beyond the average student at this point.

notka56 [123]3 years ago

5 0

<span><span>Step 1 Divide all terms by a (the coefficient of x2).</span>Step 2 Move the number term (c/a) to the right side of the equation.<span>Step 3 Complete the square on the left side of the equation and balance this by adding the same value to the right side of the equation.</span></span>

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Number two please <br> ASAP

miv72 [106K]

The solutions for $-5 +2x^{2} = -6x$ is option 3. $x= \frac{-6 \pm \sqrt{36-4 (2)(-5)}}{4} .$

Step-by-step explanation:

Step 1:

First, we must bring the equation to the form of $ax^{2} +bx +c =0.$

So $-5 +2x^{2} = -6x$ becomes $2x^{2} +6x-5=0.$

The value of a is the coefficient of the $x^{2}$ term, the value of b is the coefficient of x term and c is the coefficient of the constant term.

Comparing the above equation to $ax^{2} +bx +c =0,$ we get $a = 2, b = 6,$ and $c=-5.$

We have the formula $x=\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}.$

Step 2:

By substituting the known values, we get

$x=\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a} =\frac{-6 \pm \sqrt{6^{2}-4 (2)(-5)}}{2 (2)}.$

$\frac{-6 \pm \sqrt{6^{2}-4 (2)(-5)}}{2 (2)} = \frac{-6 \pm \sqrt{36-4 (2)(-5)}}{4} .$

This is the third option.

8 0

4 years ago

STATISTICS PLEASE HELP

Bingel [31]

Answer:

95

Step-by-step explanation:

If the mean is 400 and the standard deviation 12.5. It means that a range between 375 and 425 is the mean +- 2 standard deviations

400 - 12.5*2 = 375

400 + 12.5*2 = 425

Which means the probability is 95%

When you are looking for +- 1 deviation standard the probability is 68, and for +- 3 the probability is 99.7

There is a more complex explanation based on Z, but assuming you are only applying 68-95-99.7 rule this should be enough.

7 0

3 years ago

How to solve 5(2b-3)-1(11b+1)=20

son4ous [18]

Answer:

b = -36

Step-by-step explanation:

Start by distributing both th 5 and the negative 1 into their corresponding parentheses.

((5*2b)-(5*3)) > (10b - 15)

((-1*11b)+(-1*1)) > (-11b - 1)

so you have:

10b - 15 - 11b - 1 = 20

Next you would Combine like terms to get:

-b - 16 = 20

Add the 16 to both sides

-b = 36

and divide each side by -1

b = - 36

hope this helps

3 0

3 years ago

In this diagram, m<br><br> Please help to be marked as brainlest

OlgaM077 [116]

Answer:

144 degrees

Step-by-step explanation:

A straight line adds up to 180 degrees so:2x+8+x-2=180

2x+x+8-2=180

3x+6=180

3x=180-6

3x/3=174/3

X=68

2x+8

2*68+8=144

6 0

3 years ago

I went to the market to sell 50 animals I sold horses for $20 I sold cows $10 each chickens I sold for only $5 each I came home

slamgirl [31]

Answer:

You possibly sold 24 horses, 1 cow, and 2 chickens. The question isn't stated.

4 0

3 years ago