I need help btw i am in middle school

Solve x/-3 = -15. A.) -45 B.) 5 C.) -5 D.) 45 this is multiple choice

Fiesta28 [93]

Answer:

x= 45

Step-by-step explanation:

x= -15*-3

x= 45

6 0

3 years ago

Solve the equation 2 cos ( x ) + 1 = 0 2 cos x + 1 = 0 , 0 ≤ x ≤ 2 π 0 ≤ x ≤ 2 π . Show all of your work

TiliK225 [7]

Answer:

2π/3, 4π/3

Step-by-step explanation:

I interpret your question as asking us to solve the equation

2cos(x) + 1 = 0

2cos(x) = -1

cos(x) = -½x

x = arccos(-½), 0 ≤ x ≤2π

Since the cosine is negative, x must be in the second or third quadrant.

Referring to the unit circle, we find that

x = 2π/3 (120°) or x = 4π/3 (240°)

8 0

3 years ago

The diameter of a circle has length 12. The center is at*(-5, 2). Give the equation

labwork [276]

Answer:

Equation of the circle is : $x^{2} + 10x + y^{2} -4y -7 =0$

Step-by-step explanation:

Let us consider the image attached in the answer area.

The center O has the co-ordinates i.e. (-5,2) and the diameter given is 12 units.

We know that radius is half of diameter.

$\text{Radius = }\dfrac{\text{Diameter}}{2}$

$\text{Radius = }\dfrac{12}{2}\\\Rightarrow \text{Radius = 6units}$

The equation for circle given the center and radius, can be represented as:

$(x-a)^{2}+ (y-b)^{2} = r^{2}$

Where (a,b) is the co-ordinate of center and r is the radius.

Let us consider the following formula:

$(p+q)^2 = p^{2}+ q^{2} +2pq\\(p-q)^2 = p^{2}+ q^{2} -2pq$

$(x-(-5))^{2}+ (y-2)^{2} = 6^{2}\\\Rightarrow (x+5)^{2}+ (y-2)^{2} = 36\\\Rightarrow x^{2} + 25 + 10x +y^{2} + 4-4y=36\\\Rightarrow x^{2} + 10x +y^{2} -4y-7=0$

Hence, Equation of the circle is : $x^{2} + 10x + y^{2} -4y -7 =0$

4 0

3 years ago

For a spear with a radius of 8 what is the surface area

UkoKoshka [18]

Solution
A=4πr2=4·π·82≈804.24772
Approximately = 804.25

6 0

3 years ago

The pentagon below has an area of 8.3 square centimeters and a side of 2.2. What is the approximate length of the apothem? A.0.4

nalin [4]

Answer:

C. 1.5 cm

Step-by-step explanation:

A pentagon is a polygon with 5 sides.

The formula for the area of a regular polygon is

$A=\frac{1}{2}ap$

where a is the apothem and p is the perimeter. The perimeter is found by multiplying the number of sides of the figure by the length of 1 of those sides:

5(2.2) = 11

Now we have everything we need to solve for the length of the apothem.

$8.3=\frac{1}{2}a(11)$

Begin by multiplying both sides by 2 to get rid of the fraction, so

16.6 = 11a Divide both sides by 11 to get

a = 1.5090909 or

C. 1.5 cm

3 0

3 years ago

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