Evaluate 47-5 times 3

The following is an example of which property?

balu736 [363]

Answer:

I think it is commutative

Step-by-step explanation:

because commute means move so I think that's what it is

3 0

3 years ago

Read 2 more answers

A househusband is cooking beef stew for his family in a pan that is (a) uncovered, (b) covered with a light lid, and (c) covered

raketka [301]

Answer:

Cooking will be shortest when the househusband covers the beef stew with the heavy lid.

Step-by-step explanation:

The explanation for this is that water boils at 100°C at normal atmospheric pressure & it remains at that temperature until all the water evaporates as steam; the temperature can then go higher in steam form.

So, if he leaves the pan uncovered the pressure above the beef stew will be the atmospheric pressure and the temperature of the stew will not pass the 100°C mark and the food cooks at 100°C.

If he places a light lid on top, the pressure will build up & the temperature at which water remains liquid is a bit higher, but eventually the steam will push the lid to escape thereby releasing pressure & reducing the temperature.

If he puts a heavy lid on the pan the pressure can build up the highest and the temperature of the water in the stew will stay the highest ensuring the fastest cooking.

Basically, the heavier the lid, greater the pressure in the pan. As the pressure gets greater, the saturation temperature at which water starts boiling will be higher. And higher boiling temperatures mean shorter cooking times.

8 0

3 years ago

Y=-x^2+2x+10 y=x+2 Substitution Please show your work Need ASAP

erik [133]

Answer:

The solutions of the system of equations are the points

$(\frac{1-\sqrt{33}} {2},\frac{5-\sqrt{33}} {2})$

$(\frac{1+\sqrt{33}} {2},\frac{5+\sqrt{33}} {2})$

Step-by-step explanation:

we have

$y=-x^{2} +2x+10$ ----> equation A

$y=x+2$ ----> equation B

Solve the system by substitution

substitute equation B in equation A

$x+2=-x^{2} +2x+10$

solve for x

$-x^{2} +2x+10-x-2=0$

$-x^{2} +x+8=0$

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

$x=\frac{-b\pm\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$-x^{2} +x+8=0$

so

$a=-1\\b=1\\c=8$

substitute in the formula

$x=\frac{-1\pm\sqrt{1^{2}-4(-1)(8)}} {2(-1)}$

$x=\frac{-1\pm\sqrt{33}} {-2}$

$x=\frac{-1+\sqrt{33}} {-2}$ -----> $x=\frac{1-\sqrt{33}} {2}$

$x=\frac{-1-\sqrt{33}} {-2}$ -----> $x=\frac{1+\sqrt{33}} {2}$

Find the values of y

For $x=\frac{1-\sqrt{33}} {2}$

$y=x+2$

$y=\frac{1-\sqrt{33}} {2}+2$ ----> $y=\frac{5-\sqrt{33}} {2}$

For $x=\frac{1+\sqrt{33}} {2}$

$y=x+2$

$y=\frac{1+\sqrt{33}} {2}+2$ ----> $y=\frac{5+\sqrt{33}} {2}$

therefore

The solutions of the system of equations are the points

$(\frac{1-\sqrt{33}} {2},\frac{5-\sqrt{33}} {2})$

$(\frac{1+\sqrt{33}} {2},\frac{5+\sqrt{33}} {2})$

5 0

2 years ago

In one day Sasha got 1 hour of sleep for every 3 hours she was awake if there are 24 hours in a day how many hours of sleep did

Gre4nikov [31]

Answer:

Hours slept = 6 hours

Hours awake = 18 hours

Step-by-step explanation:

Sasha got 1 hour of sleep for every 3 hours she was awake.

So,

This means:

Slept : Awake = 1 : 3

Total hours in a day = 24 hours

Let

Hours slept = 1x and hours awake = 3x

Hence,

1x + 3x = 24 hours

4x = 24

Divide both sides by 4

x = 24 / 4

x = 6

So,

Hours slept = 1(6) = 6 hours

Hours awake = 3(6) = 18 hours

$\rule[225]{225}{2}$

Hope this helped!

6 0

2 years ago

A manufacturing process produces semiconductor chips with a known failure rate of . If a random sample of chips is selected, app

AleksandrR [38]

Answer:

The probability that at least 14 of the chips will be defective is 0.6664.

Step-by-step explanation:

The complete question is:

A manufacturing process produces semiconductor chips with a known failure rate of 5.4%. If a random sample of 300 chips is selected, approximate the probability that at least 14 will be defective. Use the normal approximation to the binomial with a correction for continuity .

Solution:

Let X = number of defective chips.

The probability that a chip is defective is, p = 0.054.

A random sample of n = 300 chips is selected.

A chip is defective or not is independent of the other chips.

The random variable X follows a Binomial distribution with parameters n = 300 and p = 0.054.

But the sample selected is too large.

So a Normal approximation to binomial can be applied to approximate the distribution of X if the following conditions are satisfied: