All categories

2 years ago

Which expression(s) have positive values? Choose

Mathematics

1 answer:

OLEGan [10]2 years ago

5 0

9514 1404 393

Answer:

2. -(-73) is positive

Step-by-step explanation:

It's not too difficult, but you can get wrapped around the axle. Here are the rules:

the opposite of a positive number is a negative number
the opposite of a negative number is a positive number

That is, turning a number to its opposite is just changing its sign.

If you layer these rules, you find ...

the opposite of (the opposite of a positive number) is a positive number

The first rule tells you the statement in parentheses is a negative number, and the second rule tell you its opposite is a positive number.

That is, a double opposite gets you back where you started. In short, any even number of minus signs cancel each other.

The numbers you have listed here* are ...

-730 (negative)
-(-73) = 73 (positive)
-75 (negative)
-(-(-701)) = -701 (negative)

_____

* We say "listed here" because we're seeing mismatched parentheses and brackets, so we know something is missing. We're going by the signs and numbers that we do see. YMMV

You might be interested in

Click an item in the list or group of pictures at the bottom of the problem and, holding the button down, drag it into the corre

Margaret [11]

In getting the area of and equilateral triangle, you must first consider that all of its sides are congruent and that is 3 inches, so the formula in getting the area is height form its base so in getting its height you must use the pythagorean theorem by dividing the triangle so the hypotenuse of it is 3 and the base of 1.5inches, so the height is 4.77 inches then the area is 7.15 sqr.inch

4 0

3 years ago

Leon has $40 How many Mexican pesos can Leon buy with his dollars Show work plz

tatuchka [14]

12x40=480
You can first multiply 12x4=48 and then you could put a zero next to the 8

5 0

3 years ago

I need help on this

Dvinal [7]

Answer:

1/12, 1/10

Step-by-step explanation:

P(Bead bracelet and red shoes) - 3/3 x 2 x 2

3/12=1/4 for bead bracelet

Red shoes - 1/3

Total probability for P(Bead bracelet and red shoes=1/4 x 1/3=1/12

P(Elastic bracelet and black shoes)

2/3 x 2 x 2

2/12=1/6 for elastic bracelet

Black shoes - 3/5

Total probablility for P(Elastic bracelet and black shoes)=1/6 x 3/5=3/10=1/10

Hope I helped!

5 0

3 years ago

A researcher wishes to estimate the average blood alcohol concentration (BAC) for drivers involved in fatal accidents who are f

Mnenie [13.5K]

Answer:

A 90% confidence interval for the mean BAC in fatal crashes in which the driver had a positive BAC is [0.143, 0.177] .

Step-by-step explanation:

We are given that a researcher randomly selects records from 60 such drivers in 2009 and determines the sample mean BAC to be 0.16 g/dL with a standard deviation of 0.080 g/dL.

Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean BAC = 0.16 g/dL

s = sample standard deviation = 0.080 g/dL

n = sample of drivers = 60

$\mu$ = population mean BAC in fatal crashes

Here for constructing a 90% confidence interval we have used a One-sample t-test statistics because we don't know about population standard deviation.

So, a 90% confidence interval for the population mean, $\mu$ is;

P(-1.672 < $t_5_9$ < 1.672) = 0.90 {As the critical value of t at 59 degrees of

freedom are -1.672 & 1.672 with P = 5%} P(-1.672 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 1.672) = 0.90

P( $-1.672 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $1.672 \times {\frac{s}{\sqrt{n} } }$ ) = 0.90

P( $\bar X-1.672 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+1.672 \times {\frac{s}{\sqrt{n} } }$ ) = 0.90

90% confidence interval for $\mu$ = [ $\bar X-1.672 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+1.672 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $0.16-1.672 \times {\frac{0.08}{\sqrt{60} } }$ , $0.16+1.672 \times {\frac{0.08}{\sqrt{60} } }$ ]

= [0.143, 0.177]

Therefore, a 90% confidence interval for the mean BAC in fatal crashes in which the driver had a positive BAC is [0.143, 0.177] .

7 0

3 years ago

Express the sum of (square root) -64 and 3(square root) -4 as a monomial in terms of I.

Inga [223]

$\bf \sqrt{-64}~+~3\sqrt{-4}\implies \sqrt{-1\cdot 2^6}~+~3\sqrt{-1\cdot 2^2}
\\\\\\
\sqrt{-1}\cdot \sqrt{2^6}~+~3\sqrt{-1}\cdot \sqrt{2^2}\implies i\cdot \sqrt{2^{3\cdot 2}}~+~3\cdot i\cdot 2
\\\\\\
i\cdot \sqrt{(2^3)^2}~~+~~6i\implies 2^3i~+~6i\implies 8i+6i\implies 14i$

7 0

3 years ago