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3 years ago

I need help please and thank you

Mathematics

1 answer:

nignag [31]3 years ago

5 0

Answer:

B. A square is a rectangle.

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What is the side length a in the triangle below?

grigory [225]

Answer:

a=5

Step-by-step explanation:

a^2+b^2=c^2

c^2-b^2=a^2

13^2-12^2=a^2

169-144=a^2

25=a^2

5=a

8 0

3 years ago

What is m<CDJ ? Enter your answer in the box.

Westkost [7]

Answer:

it is cGh

Step-by-step explanation:

6 0

3 years ago

Every chemical element goes through natural exponential decay, which means that over time its atoms fall apart. The speed of eac

Lesechka [4]

Answer:

$Q(t) = 800e^{-0.0495t}$

Step-by-step explanation:

The amount of the isotope after t seconds is given by the following exponential equation:

$Q(t) = Q(0)e^{-rt}$

In which Q(0) is the initial amount and r is the decay rate.

A sample of beryllium-11 was first measured to have 800 atoms.

This means that $Q(0) = 800$

The half-life of the isotope beryllium-11 is 14 seconds.

This means that $Q(14) = 0.5Q(0)$

We use this to find r.

$Q(t) = Q(0)e^{-rt}$

$0.5Q(0) = Q(0)e^{-14r}$

$e^{-14r} = 0.5$

$\ln{e^{-14r}} = \ln{0.5}$

$-14r = \ln{0.5}$

$r = -\frac{\ln{0.5}}{14}$

$r = 0.0495$

$Q(t) = Q(0)e^{-rt}$

$Q(t) = 800e^{-0.0495t}$

8 0

4 years ago

Jay J runs of a 1/3 mile in 4 minutes. A. If Jay J continues at the same speed, how long will it take her to run one mile?

Marat540 [252]

$\bf \begin{array}{ccll} miles&minutes\\ \cline{1-2} \frac{1}{3}&4\\\\ 1&x \end{array}\implies \cfrac{~~\frac{1}{3}~~}{1}=\cfrac{4}{x}\implies \cfrac{1}{3}=\cfrac{4}{x}\implies x=12$

4 0

4 years ago

2/3(2x-1)+2 1/3=7+1/2x

schepotkina [342]

$Answer: x=4/5$

Step 1

$2/3*2*(2*x-1)-x+2*7-7*2 = 0\\5/3*x-14-4/3+14 = 0\\5/3*x-14+38/3 = 0$

Step 2

$5/3*x-4/3 = 0\\(5/3*x-4/3)/2 = 0\\(5/3*x-4/3)/2 = 0 // * 2\\5/3*x-4/3 = 0$

Step 3

$5/3*x-4/3 = 0 // + 4/3\\5/3*x = 4/3 // : 5/3\\x = 4/3/5/3\\x = 4/5$

3 0

3 years ago