You said that (xy) = 16, and (x+y) = 4 .

From the second equation you can get [ x = 4 - y ],
then substitude that for 'x' in the first equation, and
finally, rearrange the first equation to read
 x² - 4x + 16 = 0

Don't even try to factor that quadratic equation. Go straight
to the quadratic formula, and the two solutions you find are ...

 x = 2 + i 2√3
and
 x = 2 - i 2√3 .

Those are the two number that do what you want.

There are no real numbers that can do it.

7 0

3 years ago

Read 2 more answers

Suppose that prices of a certain model of new homes are normally distributed with a mean of $150,000. use the 68-95-99.7 rule to

Novosadov [1.4K]

Answer:

We want to find the percentage of values between 147700 and 152300

$P(147700$

And one way to solve this is use a formula called z score in order to find the number of deviations from the mean for the limits given:

$z= \frac{x-\mu}{\sigma}$

And replacing we got:

$z=\frac{147700-150000}{2300}=-1$

$z=\frac{152300-150000}{2300}=1$

So then we are within 1 deviation from the mean so then we can conclude that the percentage of values between $147,700 and $152,300 is 68%

Step-by-step explanation:

We define the random variable representing the prices of a certain model as X and the distirbution for this random variable is given by:

$X \sim N(\mu = 150000, \sigma =2300$

The empirical rule states that within one deviation from the mean we have 68% of the data, within 2 deviations from the mean we have 95% and within 3 deviations 99.7 % of the data.