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3 years ago

Select the expression equivalent to (-2x + 8.1y) - (-9x + 5.3y).

Mathematics

1 answer:

andre [41]3 years ago

8 0

Answer:

the answer is d

Step-by-step explanation:

you need to combined like term

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g Make a decision about the given claim. Use only the rare event rule, and make subjective estimates to determine whether event

vagabundo [1.1K]

Answer:

There is not sufficient evidence to support the claim.

Step-by-step explanation:

The claim to be tested is:

The mean respiration rate (in breaths per minute) of students in a large statistics class is less than 32.

To test this claim the hypothesis can be defined as follows:

H₀: The mean respiration rate of students is 32, i.e. μ = 32.

Hₐ: The mean respiration rate of students is less than 32, i.e. μ < 32.

The sample mean respiration rate of students is 31.3.

According to the claim the sample mean is less than 32.

The sample mean value is not unusual if the claim is true, and the sample mean value is also not unusual if the claim is false.

Thus, there is not sufficient evidence to support the claim.

7 0

3 years ago

Find the dimensions of the open rectangular box of maximum volume that can be made from a sheet of cardboard 11 in. by 7 in. by

11111nata11111 [884]

Answer:

The dimension of the open rectangular box is $8.216\times 4.216\times 1.392$ .

The volume of the box is 8.217 cubic inches.

Step-by-step explanation:

Given : The open rectangular box of maximum volume that can be made from a sheet of cardboard 11 in. by 7 in. by cutting congruent squares from the corners and folding up the sides.

To find : The dimensions and the volume of the open rectangular box ?

Solution :

Let the height be 'x'.

The length of the box is '11-2x'.

The breadth of the box is '7-2x'.

The volume of the box is $V=l\times b\times h$

$V=(11-2x)\times (7-2x)\times x$

$V=4x^3-36x^2+77x$

Derivate w.r.t x,

$V'(x)=4(3x^2)-2(36x)+77$

$V'(x)=12x^2-72x+77$

The critical point when V'(x)=0

$12x^2-72x+77=0$

Solve by quadratic formula,

$x=\frac{18+\sqrt{93}}{6},\frac{18-\sqrt{93}}{6}$

$x=4.607,1.392$

Derivate again w.r.t x,

$V''(x)=24x-72$

Now, $V''(4.607)=24(4.607)-72=38.568>0$ (+ve)

$V''(1.392)=24(1.392)-72=-38.592$ (-ve)

So, there is maximum at x=1.392.

The length of the box is $l=11-2x$

$l=11-2(1.392)=8.216$

The breadth of the box is $b=7-2x$

$b=7-2(1.392)=4.216$

The height of the box is h=1.392.

The dimension of the open rectangular box is $8.216\times 4.216\times 1.392$ .

The volume of the box is $V=l\times b\times h$

$V=8.216\times 4.216\times 1.392$

$V=48.217\ in.^3$

The volume of the box is 8.217 cubic inches.

5 0

3 years ago

A chef uses 2 3 cup of flour for every 1 8 cup of water in a dough recipe. If the chef follows the recipe proportions, which sta

VashaNatasha [74]

Step-by-step explanation:

A chef uses 2/3 cup of flour for every 1/8 cup of water in a dough recipe.

It means,

2/3 cup = 1/8 cup of water

$1\ \text{cup}=\dfrac{\dfrac{1}{8}}{\dfrac{2}{3}}\\\\=0.1875$

Hence, the constant of proportionality is 0.1875.

5 0

3 years ago

How does 1/8 divided by 1/4 equal 1/2?

photoshop1234 [79]

When you divide a fraction by a fraction, you're really just multiplying by a reciprocal. A reciprocal is the fraction flipped around.
So, 1/8 ÷ 1/4 is the same thing as 1/8 x 4/1
Now, you just multiply. 1 times 4 is 4. 8 times 1 is 8.
1/8 x 4/1=4/8
4/8 simplified is 1/2
So that is how 1/8÷1/4=1/2

6 0

3 years ago

Write 6 2/3 as a improper fraction

kirill115 [55]

Hi, i think the answer 20/3 hope this helped :D

3 0

3 years ago

Read 2 more answers