Help??will mark brainlest

Can the exponent in the denominator be subtracted from the exponent in the numerator when the based are different? Explain

Vanyuwa [196]

Answer:

No, Sorry.

Step-by-step explanation:

Since the bases are different, you'll have to change them even if they have a exponent or not. If you dunno how to make the denominators the same, just multiply the two by eachother.

Example) 1/2 - 3/4

$\frac{1}{2} - \frac{3}{4}$

Multiply 2 and 4 together, and then multiply the 4 to the one also. Multiply 2 to four and also to the 3.

$\frac{4}{8} - \frac{6}{8}$

The subtract from there.

$\frac{ - 2}{8}$

and then Reduce (if needed.)

$\frac{ - 1}{4}$

4 0

2 years ago

In the figure below, BD and EC are diameters of circle P.

Zinaida [17]

Answer: 333 degrees

Step-by-step explanation:

8 0

3 years ago

A random sample of 20 students yielded a mean of ¯x = 72 and a variance of s2 = 16 for scores on a college placement test in mat

Helen [10]

Answer:

The 98% confidence interval for the variance in the pounds of impurities would be $8.400 \leq \sigma^2 \leq 39.827$ .

Step-by-step explanation:

1) Data given and notation

$s^2 =16$ represent the sample variance

s=4 represent the sample standard deviation

$\bar x$ represent the sample mean

n=20 the sample size

Confidence=98% or 0.98

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population mean or variance lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

The Chi square distribution is the distribution of the sum of squared standard normal deviates .

2) Calculating the confidence interval

The confidence interval for the population variance is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma^2 \leq \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

On this case the sample variance is given and for the sample deviation is just the square root of the sample variance.

The next step would be calculate the critical values. First we need to calculate the degrees of freedom given by:

$df=n-1=20-1=19$

Since the Confidence is 0.98 or 98%, the value of $\alpha=0.02$ and $\alpha/2 =0.01$ , and we can use excel, a calculator or a table to find the critical values.

The excel commands would be: "=CHISQ.INV(0.01,19)" "=CHISQ.INV(0.99,19)". so for this case the critical values are:

$\chi^2_{\alpha/2}=36.191$

$\chi^2_{1- \alpha/2}=7.633$

And replacing into the formula for the interval we got:

$\frac{(19)(16)}{36.191} \leq \sigma^2 \leq \frac{(19)(16)}{7.633}$

$8.400 \leq \sigma^2 \leq 39.827$

So the 98% confidence interval for the variance in the pounds of impurities would be $8.400 \leq \sigma^2 \leq 39.827$ .

7 0

3 years ago

Rewrite these expressions using words. 2 1/4 +8/3

ElenaW [278]

Answer:

two and one fourths plus eight thirds

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers

Awesome Car company sold 20 cars this week.their goal is to sell at least 25% more next week. Write an inequality that represent

Serga [27]

Twenty-five percent (25%) of 20 is equal to 5. Therefore, the company is planning or targeting to sell at least 25 cars next week. We let the number of cars be x. The inequality that best represent the scenario above is,
x ≥ 25

6 0

3 years ago

Read 2 more answers