All categories

3 years ago

X^2 -2x -1 = 0 Pls help...show work and the answer

Mathematics

1 answer:

stepladder [879]3 years ago

3 0

$x^2-2x-1=x^2-2x+1-2=(x-1)^2-2=0$

Solve for $x$ :

$(x-1)^2-2=0$
$(x-1)^2=2$
$x-1=\pm\sqrt2$
$x=1\pm\sqrt2$

You might be interested in

Expand and simplify bracket please quickly

natulia [17]

Answer:

4y²-1/4 is the required answer

Step-by-step explanation:

$(2y - \frac{1 }{2} )(2y + \frac{1}{2} ) \\ using \: formula \: {x}^{2} - y {}^{2} = (x - y)(x + y) \\ 4y {}^{2} - \frac{1}{4}$

4 0

2 years ago

To illustrate the effects of driving under the influence of alcohol, a police officer brought a DUI simulator to a local high sc

nexus9112 [7]

Answer:

Check the explanation

Step-by-step explanation:

Here we have to first of all carry out dependent sample t test. consequently wore goggles first was selected at random for the reason that the reaction time in an emergency taken with goggles would be greater than the amount of reaction time in an emergency taken with not so weakened vision. So that we will get the positive differences d = impaired - normal

To find 95% confidence interval first we need to find sample mean and sample sd for difference d = impaired minus normal.

We can find it using excel that is in the first attached image below,

Therefore sample mean $( \bar{X}_{d} )$ = 0.98

Sample sd $( \bar{S}_{d} )$ = 0.3788

To find 95% Confidence interval we can use TI-84 calculator,

Press STAT ----> Scroll to TESTS ---- > Scroll down to 8: T Interval and hit enter.

Kindly check the attached image below.

Therefore we are 95% confident that mean difference in braking time with impaired vision and normal vision is between ( 0.6888 , 1.2712)

Conclusion : As both values in the interval are greater than 0 , mean difference impaired minus normal is not equal to 0

There is significant evidence that there is a difference in braking time with impaired vision and normal vision at 95% confidence level .

7 0

3 years ago

My original lenguaje is Spanish so I'm really bad in English.

NNADVOKAT [17]

Step-by-step explanation:

lo siento much solo si fuera Buena con matimaticas.

6 0

3 years ago

What is the equation of the line?

sergiy2304 [10]

Answer:

y= -1x+3

Step-by-step explanation:

4 0

3 years ago

two mechanics worked on a car. the first mechanic charged $45 per hour, and the second mechanic charged $120 per hour. the mecha

BlackZzzverrR [31]

<u>Answer:</u>

First mechanic worked for 20 hours and second mechanic worked for 15 hours.

<u>Solution:</u>

Given, Two mechanics worked on a car.

The first mechanic charged $45 per hour, and the second mechanic charged $120 per hour.

The mechanics worked for a combined total of 35 hours, and together they charged a total of $2700.

We have to find how long did each mechanic work.

Let the time worked by 1st mechanic be t hours then time taken by 2nd mechanic will be 35 – t hours.

Now, according to given information,

45 x t + 120 $\times$ (35 – t) = 2700

45t + 120 $\times$ 35 – 120t = 2700

-75t + 4200 = 2700

75t = 4200 – 2700

75t = 1500

t = 20

hence, 1st mechanic worked for 20 hours and 2nd mechanic worked for 35 – 20 = 15 hours.

4 0

4 years ago