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2 years ago

What is the value of the expression 8.3 × 104 − 2.5 × 103 − 1.9 × 104 written in scientific notation?

2 answers:

4 0

Remark work with the two numbers that are 10^4 first. Then add in the one that goes to 10^3

Method one
You could change these all to integers and then take it back to scientific notation.

83 000
-19 000
64 000
- 2 500
 61 500 <<<<<< answer

Method two
Keep the scientific notation.
8.3 * 10^4
-1.9 * 10^4
6.4 * 10^4
- .25*10^4 Note the powers of ten must be the same.
6.15*10^4 <<<<<<<< answer

Either method works.

You could use your calculator to get the right answer. I'm not sure all calculators retain the scientific notation. Test yours to see what it does. Enter 8.3*10y^x 4 *1 =

Your calculator might have x^y or ^ to record powers. You may also have EE and one of your keys.

See if your calculator returns 8.3*10^4 or if it returns 83000

Nady [450]2 years ago

4 0

I believe it is 4.081x10^2

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Solve h-w Solve m = for the 8 variable h. I

Ilya [14]

Answer:

1) m = h - w/8

Subtract h from both sides.

m - h = -w/8

Subtract m from both sides.

-h = -m - w/8

Divide all terms by -1.

h = m + w/8.

2) m = h - w/8

Get rid of the denominator 8 by multiplying 8/1 to all terms.

8m = 8h - w

Add w on both sides and subtract 8m from both sides.

w = 8h - 8m

3) w = x + y/z

Get rid of the denominator z by multiplying it to all terms.

wz = xz + y

Subtract xz from both sides of the equation.

wz - xz = y OR y = wz - xz

4) w = x + y/z

Subtract x from both sides.

w - x = y/z

Get rid of the denominator by multiplying it to all terms.

wz - xz = y

Now factor the expression wz - xz.

z(w - x) = y

Divide both sides by w - x.

z = y / w - x

This is read as z equals to y divided by w minus x.

5) The area of a triangle is A = 1/2bh

First, get rid of the denominator by multiplying both sides by 2.

2A = bh

To find b, divide both sides by h.

2A/h = b

6) P = kt/v

Multiply both sides by v.

Pv = kt

Divide both sides by t.

Pv/t = k OR k = Pv/t.

Step-by-step explanation:

8 0

2 years ago

Find the next 3 terms in the geometric sequence -36, 6, -1, 1/6, ...

timama [110]

we are given

geometric sequence -36, 6, -1, 1/6, ...

first term is -36

$a_1=-36$

now, we can find common ratio

$r=\frac{6}{-36}$

$r=-\frac{1}{6}$

now, we can find nth term

$a_n=a_1(r)^{n-1}$

now, we can plug values

and we get

$a_n=36(-\frac{1}{6})^{n-1}$

now, we can find 5th term , 6th term, 7th term

fifth term:

$a_5=36(-\frac{1}{6})^{4}$

$a_5=\frac{1}{36}$

sixth term:

$a_6=36(-\frac{1}{6})^{5}$

$a_6=-\frac{1}{216}$

seventh term:

$a_7=36(-\frac{1}{6})^{6}$

$a_7=\frac{1}{1296}$

so, next terms are

$a_5=\frac{1}{36}$ , $a_6=-\frac{1}{216}$

, $a_7=\frac{1}{1296}$ .............Answer

6 0

3 years ago

In the past, the average age of employees of a large corporation has been 40 years. Recently, the company has been hiring older

Viktor [21]

Answer:

$p_v =P(t_{(63)}>2.5)=0.0075$

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can conclude that the mean age is significantly higher than 45 years at 5% of significance.

Step-by-step explanation:

1) Data given and notation

$\bar X=45$ represent the mean height for the sample

$s=16$ represent the sample standard deviation for the sample

$n=64$ sample size

$\mu_o =40$ represent the value that we want to test

$\alpha=0.05$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean age is higher than 40 years, the system of hypothesis would be:

Null hypothesis: $\mu \leq 40$

Alternative hypothesis: $\mu > 40$

If we analyze the size for the sample is < 30 and we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{45-40}{\frac{16}{\sqrt{64}}}=2.5$