All categories

2 years ago

Work out the area of the circle and leave it in cm plz

Mathematics

2 answers:

Marat540 [252]2 years ago

5 0

Answer:

132.7495 cm^2

Step-by-step explanation:

area of circle=πr^2

radius=6.5

6.5^2

42.25

42.25*3.142

132.7495

miskamm [114]2 years ago

3 0

Answer:

132.7495 cm

Step-by-step explanation:

13/2=6.5

6.5*6.5=42.25

42.25*3.142=132.1495

You might be interested in

If ac =14 find the value of x then find ab and bc

Igoryamba

Answer:

If B is between A and C, AB = x, BC = 2x + 2, and AC = 14, find the value of x. Then find AB and BC.

Step-by-step explanation:

AB=x

BC = 2x + 2BC=2x+2

AC =14AC=14

Required

Determine x, AB and BC.

Since B is between A and C;

AB + BC = ACAB+BC=AC

Substitute x for AB; 2x + 2 for BC and 14 for AC

x + 2x + 2 = 14x+2x+2=14

3x + 2 = 143x+2=14

Collect Like Terms

3x = 14 - 23x=14−2

3x = 123x=12 '

x = \frac{12}{3}x=

x = 4x=4

Substitute 4 for x in

AB = xAB=x

BC = 2x + 2BC=2x+2

AB = 4AB=4

BC = 2(4) + 2BC=2(4)+2

BC = 8 + 2BC=8+2

BC = 10BC=10

3 0

1 year ago

Use the exponential decay model, Upper A equals Upper A 0 e Superscript kt, to solve the following. The half-life of a certai

Akimi4 [234]

Answer:

It will take 7 years ( approx )

Step-by-step explanation:

Given equation that shows the amount of the substance after t years,

$A=A_0 e^{kt}$

Where,

$A_0$ = Initial amount of the substance,

If the half life of the substance is 19 years,

Then if t = 19, amount of the substance = $\frac{A_0}{2}$ ,

i.e.

$\frac{A_0}{2}=A_0 e^{19k}$

$\frac{1}{2} = e^{19k}$

$0.5 = e^{19k}$

Taking ln both sides,

$\ln(0.5) = \ln(e^{19k})$

$\ln(0.5) = 19k$

$\implies k = \frac{\ln(0.5)}{19}\approx -0.03648$

Now, if the substance to decay to 78% of its original amount,

Then $A=78\% \text{ of }A_0 =\frac{78A_0}{100}=0.78 A_0$

$0.78 A_0=A_0 e^{-0.03648t}$

$0.78 = e^{-0.03648t}$

Again taking ln both sides,

$\ln(0.78) = -0.03648t$

$-0.24846=-0.03648t$

$\implies t = \frac{0.24846}{0.03648}=6.81085\approx 7$

Hence, approximately the substance would be 78% of its initial value after 7 years.

5 0

2 years ago

Write this ratio as a fraction in simplest form without any units. 5 weeks to 10 days

faltersainse [42]

1/2. If you take out the units you're left with 5 to 10 or 5/10. 5 is half of 10 therefore the simplest form would be 1/2.

6 0

2 years ago

Square root of 4×-1=5

borishaifa [10]

Answer:3/2

how i did this

 Add 11 to both sides.

4x=5+1

Simplify 5+15+1 to 66.

4x=6

Divide both sides by 4

x= 6/4

Simplify 6/4 to 3/2

Awnser

x=3/2

Sorry if not helpful just trying my best :)

5 0

2 years ago

What is the slope-intercept form of the equation y - 7= -5/2(x+4)

GREYUIT [131]

The first thing I would probably do is distribute (multiply) the -5/2 into the parenthesis:

= (-5/2)x + (-20/2)

Notice how I am not putting the x into the fraction. This is to make it easier to see the slope-intercept form.

Lets simplify the (-20/2) and then add 7 to both sides:

y - 7 = (-5/2)x - 10

y = (-5/2)x - 3

Your answer would then be:

y = (-5/2)x - 3

y = mx + b

Since it is now in the requested format.

4 0

2 years ago