How many students in the survey said that math was their favorite subject?

Find the area of the shaded segment of the circle.

vredina [299]

Answer:

Around 5.5 square meters

Step-by-step explanation:

You can start by finding the area of the segment. Since the rest of the circle that is not in the segment is 240 degrees, the segment is 120 degrees or a third of the circle. You can therefore find the area of that segment with the formula $\frac{1}{3} \pi r^2 =3\pi$ square meters. Now, you need to find the area of the triangle inside the sector. This is more difficult than last time, because it is not a 90 degree angle. However, you can solve this by dividing this triangle into two 30-60-90 triangles, which you know how to find the ratio of sides for. In a 30-60-90 triangle, the hypotenuse is twice the length of the smallest leg, and the larger leg is $\sqrt{3}$ times larger than the smaller leg. In this case, these dimensions are a base of $\frac{3}{2}$ for the smaller leg and $\frac{3\sqrt{3}}{2}$ for the larger leg, or the base. Using the triangle area formula and multiplying by 2 (because remember, we divided the big triangle in half), you get $\frac{9\sqrt{3}}{4}$ square meters. Subtracting this from the area of the segment, you get about 5.5 square meters. Hope this helps!

5 0

3 years ago

Find the surface area and volume of each figure. Round each answer to the nearest hundredth.

Llana [10]

Answer: Surface area is equal to 200 $cm^{2}$

Volume is equal to 333.33 $cm^{3}$

Step-by-step explanation:

First, let's do surface area.

The surface area of a pyramid is equal to 1/2(perimeter of base)(lateral height) + area of the base

The perimeter of the base is 10(4) = 40; as the base is a square with a side length of 10.

The lateral height is given as 5 cm.

The area of the base is 10(10) = 100.

We can plug those numbers into the equation to get 1/2(40)(5) + 100, which comes out to be 200 $cm^{2}$ .

Now for volume.

The volume of a pyramid is equal to 1/3(area of the base)(height).

We already have the area of the base, which is 100.

The height is given as 10 cm.

Plugging those numbers into the equation, we get 1/3(100)(10), which is 1000/3 or about 333.33 $cm^{3}$ .

Hope this helps!

6 0

3 years ago

which expressions are equivalent to the first one? I don't understand how to determine that so please explain. Thanks!

coldgirl [10]

9514 1404 393

Answer:

(a) -(x+7)/y

(b) (x+7)/-y

Step-by-step explanation:

There are several ways you can show expressions are equivalent. Perhaps the easiest and best is to put them in the same form. For an expression such as this, I prefer the form of answer (a), where the minus sign is factored out and the numerator and denominator have positive coefficients.

The given expression with -1 factored out is ...

$\dfrac{-x-7}{y}=\dfrac{1(x+7)}{y}=\boxed{-\dfrac{x+7}{y}} \quad\text{matches A}$

Likewise, the expression of (b) with the minus sign factored out is ...

$\dfrac{x+7}{-y}=\boxed{-\dfrac{x+7}{y}}$

On the other hand, simplifying expression (c) gives something different.

$\dfrac{-x-7}{-y}=\dfrac{-(x+7)}{-(y)}=\dfrac{x+7}{y} \qquad\text{opposite the given expression}$

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Another way you can write the expression is term-by-term with the terms in alpha-numeric sequence (so they're more easily compared).

Given: (-x-7)/y = (-x/y) +(-7/y)

(a) -(x+7)/y = (-x/y) +(-7/y)

(b) (x+7)/(-y) = (-x/y) +(-7/y)

(c) (-x-7)/(-y) = (x/y) +(7/y) . . . . not the same.

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Of course, you need to know the use of the distributive property and the rules of signs.

a(b+c) = ab +ac

-a/b = a/(-b) = -(a/b)

-a/(-b) = a/b

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Summary: The given expression matches (a) and (b).

_____

Additional comments

Sometimes, when I'm really stuck trying to see if two expressions are equal, I subtract one from the other. If the difference is zero, then I know they are the same. Looking at (b), we could compute ...

$\left(\dfrac{-x-7}{y}\right)-\left(\dfrac{x+7}{-y}\right)=\dfrac{-y(-x-7)-y(x+7)}{-y^2}\\\\=\dfrac{xy+7y-xy-7y}{-y^2}=\dfrac{0}{-y^2}=0$

Yet another way to check is to substitute numbers for the variables. It is a good idea to use (at least) one more set of numbers than there are variables, just to make sure you didn't accidentally find a solution where the expressions happen to be equal. We can use (x, y) = (1, 2), (2, 3), and (3, 5) for example.

The given expression evaluates to (-1-7)/2 = -4, (-2-7)/3 = -3, and (-3-7)/5 = -2.

(a) evaluates to -(1+7)/2 = -4, -(2+7)/3 = -3, -(3+7)/5 = -2, same as given

(b) evaluates to (1+7)/-2 = -4, (2+7)/-3 = -3, (3+7)/-5 = -2, same as given

(c) evaluates to (-1-7)/-2 = 4, different from given

3 0

2 years ago

Find the solution to the system by the substitution method

sertanlavr [38]

The solution is (6,-3)

8 0

3 years ago

Nada drinks 54 glasses of water a week. How many glasses of water does she drink in 9 Weeks?

kodGreya [7K]

Answer: 486 glasses of water in 9 weeks

Step-by-step explanation:

54 X 9 = 486

Or you could add 54 to itself 9 times then you will get 486

4 0

2 years ago