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2 years ago

Element X is a radioactive isotope such that every 20 years, its mass

Mathematics

1 answer:

faust18 [17]2 years ago

3 0

Answer:

12.1

Step-by-step explanation:

y=a(1/2)^t/h

270=410(1/2)^t/20

Divide both sides by 410

0.6585365854 = (1/2)^t/20

Log Both sides

Log(0.6585365854) / Log(1/2)

.6026645024= t/20

20 x .6026645024 = t

12.05329005 to the nearest tenth is 12.1 = t

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The number of girls in cobbs class is 2 less than 3 times the number of boys. She has 26 students in her class how many are boys

Natalka [10]

Answer:

7 are boys

Step-by-step explanation:

Make a system of equations where g is for girls and b is for boys.

b+g=26

g=3b-2

Substitute "3b-2" in for "g" in the first equation.

b+(3b-2)=26

Rewrite without the parentheses because it's addition and not multiplication.

b+3b-2=26

Combine like terms.

4b-2=26

Add 2 to both sides.

4b=28

Divide by the coefficient of the variable to get it alone.

b=7

3 0

3 years ago

What simple interest rate would allow $6000 to grow to an amount of $14550 in 10 years?

Harman [31]

Answer:

$\boxed{ \bold{ \huge{ \boxed{ \sf{ \: 14.25 \: \% \: }}}}}$

Step-by-step explanation:

Given,

Principal ( P ) = $ 6000

Amount ( A ) = $ 14550

Time ( T ) = 10 years

Rate ( R ) = ?

Finding the Interest

The sum of principal and interest is called an amount.

From the definition,

$\boxed{ \sf{Amount = \: Principal + Interest}}$

plug the values

⇒ $\sf{14550 = 6000 + Interest}$

Swap the sides of the equation

⇒ $\sf{6000 + Interest = 14550}$

Move 6000 to right hand side and change its sign

⇒ $\sf{Interest = 14550 - 6000}$

Subtract 6000 from 14550

⇒ $\sf{Interest = \: 8550 \: }$

Interest = $ 8550

Finding the rate 

${ \boxed{ \sf{Rate = \frac{Interest \times 100}{Principal \times Time}}}}$

plug the values

⇒ $\sf{ Rate = \frac{8550 \times 100}{6000 \times 10} }$

Calculate

⇒ $\sf{Rate = \frac{855000}{60000} }$

⇒ $\sf{Rate = 14.25 \: \% \: }$

Hope I helped!

Best regards!!

8 0

2 years ago

Emergency I need help I don't understand this

lora16 [44]

Answer:

108 is your answer.

Step-by-step explanation:

1 x + 2x + 3x = 180

10 x = 180

x = 180/ 10

x = 18

Then

18 X 6 = 108

I HOPE IT WILL HELP YOU.

Have a great day.

it's me Sopnila.

❤❤❤

8 0

2 years ago

Read 2 more answers

Please and thank you help me

Leona [35]

Answer:

y = 3x - 5

Step-by-step explanation:

y = mx + b

m (slope) = 3/1 or 3

b (y-intercept) = -5

y = 3x - 5

8 0

2 years ago

Evaluate the following integral using trigonometric substitution

serg [7]

Answer:

The result of the integral is:

$\arcsin{(\frac{x}{3})} + C$

Step-by-step explanation:

We are given the following integral:

$\int \frac{dx}{\sqrt{9-x^2}}$

Trigonometric substitution:

We have the term in the following format: $a^2 - x^2$ , in which a = 3.

In this case, the substitution is given by:

$x = a\sin{\theta}$

$dx = a\cos{\theta}d\theta$

In this question:

$a = 3$

$x = 3\sin{\theta}$

$dx = 3\cos{\theta}d\theta$

$\int \frac{3\cos{\theta}d\theta}{\sqrt{9-(3\sin{\theta})^2}} = \int \frac{3\cos{\theta}d\theta}{\sqrt{9 - 9\sin^{2}{\theta}}} = \int \frac{3\cos{\theta}d\theta}{\sqrt{9(1 - \sin^{\theta})}}$

We have the following trigonometric identity:

$\sin^{2}{\theta} + \cos^{2}{\theta} = 1$

$1 - \sin^{2}{\theta} = \cos^{2}{\theta}$

Replacing into the integral:

$\int \frac{3\cos{\theta}d\theta}{\sqrt{9(1 - \sin^{2}{\theta})}} = \int{\frac{3\cos{\theta}d\theta}{\sqrt{9\cos^{2}{\theta}}} = \int \frac{3\cos{\theta}d\theta}{3\cos{\theta}} = \int d\theta = \theta + C$

Coming back to x:

We have that:

$x = 3\sin{\theta}$

$\sin{\theta} = \frac{x}{3}$

Applying the arcsine(inverse sine) function to both sides, we get that:

$\theta = \arcsin{(\frac{x}{3})}$

The result of the integral is:

$\arcsin{(\frac{x}{3})} + C$

8 0

2 years ago