Briana is getting materials for a chemistry experiment

Can help me complete this problem please :c

motikmotik

Answer:

$A = \dfrac{7}{2}\pi~cm^2$

Step-by-step explanation:

There is a formula for the area of a sector given the radius and the angle measure.

$A = \dfrac{n}{360^\circ}\pi r$

n = angle measure

r = radius

$A = \dfrac{140^\circ}{360^\circ}\pi \times (3~cm)^2$

$A = \dfrac{14}{36}\pi \times 9~cm^2$

$A = \dfrac{7}{18}\pi \times 9~cm^2$

$A = \dfrac{7}{2}\pi~cm^2$

3 0

3 years ago

Read 2 more answers

a father is now 38 years older than his son. Ten years ago he was twice as old as his son. let x represent the age of the son no

Helga [31]

The present age of father is 86 years old and present age of son is 48 years old

Solution:

Given that, a father is now 38 years older than his son

Ten years ago he was twice as old as his son

Let "x" be the age of son now

Therefore, from given,

Father age now = 38 + age of son now

Father age now = 38 + x

Ten years ago he was twice as old as his son

Age of son ten years ago = age of son now - 10

Age of son ten years ago = x - 10

Age of father ten years ago = 38 + x - 10

Then we get,

Age of father ten years ago = twice the age of son ten years ago

38 + x - 10 = 2(x - 10)

28 + x = 2x - 20

2x - x = 28 + 20

x = 48

Thus son age now is 48 years old

Father age now = x + 38 = 48 + 38 = 86

Thus present age of father is 86 years old and present age of son is 48 years old

7 0

3 years ago

-7^-2 does anyone know ?

Leno4ka [110]

Negative exponents mean that you flip the number upside down

so -7^-2 would become 1/-7^2

-7^2 would be 49

so the answer is 1/49

8 0

2 years ago

Read 2 more answers

What are the x-intercepts of the equation? <img src="https://tex.z-dn.net/?f=r%28x%29%20%3D%20x-1%2Fx%2B4" id="TexFormula1"

cestrela7 [59]

Answer:

The only x-intercept is x = 1

Step-by-step explanation:

The equation is:

$r(x)=\frac{x-1}{x+4}$

We can substitute y for r(x), to write in the notation:

$r(x)=\frac{x-1}{x+4}\\y=\frac{x-1}{x+4}$

To get y-intercept, we put x = 0

and

To get x-intercept, we put y =0

We want to find x-intercepts here, so we substitute 0 into y and solve for x. Shown below:

$y=\frac{x-1}{x+4}\\0=\frac{x-1}{x+4}\\0(x+4)=x-1\\0=x-1\\x=1$

The only x-intercept is x = 1

3 0

3 years ago

The formula F= 9 5 ( C)+32 converts a temperature reading from Celsius into Fahrenheit. What does 20° C convert to in terms of d

Helga [31]

Answer:

F = 9 / 5 * 20 + 32 = 9 * 4 + 32 = 68 deg F

Step-by-step explanation:

8 0

2 years ago