All categories

3 years ago

Mr. Green is putting lights around 8 windows; each window is 3.5feet wide and 5 feet long. How many feet of light does he need?

1 answer:

6 0

We must find the perimeter of all eight windows. To make it simpler for us, let's find the perimeter of one window and multiply it by 8.

2*3.5 + 2*5 = 7 + 10 = 17

17*8 = 136

Hope this helps!

You might be interested in

Determine if 9 is rational or irrational and give a reason for your answer.

Irina18 [472]

Answer:

9 is an rational number because it is a whole number

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

Which polygon in the diagram cannot be mapped onto the others by similarity transformations?

Rom4ik [11]

Answer: B.) PQRST

Step-by-step explanation:

There are no options but if its the same question I just had on a test then this is the answer..

Hope this helps..

6 0

2 years ago

You want to buy a pair of sneakers at a shoe store and you can spend at most $80 you have a coupon for $10 off any pair of shoes

PolarNik [594]

80 $\geq$ p-20

3 0

3 years ago

Suppose after 2500 years an initial amount of 1000 grams of a radioactive substance has decayed to 75 grams. What is the half-li

krok68 [10]

Answer:

The correct answer is:

Between 600 and 700 years (B)

Step-by-step explanation:

At a constant decay rate, the half-life of a radioactive substance is the time taken for the substance to decay to half of its original mass. The formula for radioactive exponential decay is given by:

$A(t) = A_0 e^{(kt)}\\where:\\A(t) = Amount\ left\ at\ time\ (t) = 75\ grams\\A_0 = initial\ amount = 1000\ grams\\k = decay\ constant\\t = time\ of\ decay = 2500\ years$

First, let us calculate the decay constant (k)

$75 = 1000 e^{(k2500)}\\dividing\ both\ sides\ by\ 1000\\0.075 = e^{(2500k)}\\taking\ natural\ logarithm\ of\ both\ sides\\In 0.075 = In (e^{2500k})\\In 0.075 = 2500k\\k = \frac{In0.075}{2500}\\ k = \frac{-2.5903}{2500} \\k = - 0.001036$

Next, let us calculate the half-life as follows:

$\frac{1}{2} A_0 = A_0 e^{(-0.001036t)}\\Dividing\ both\ sides\ by\ A_0\\ \frac{1}{2} = e^{-0.001036t}\\taking\ natural\ logarithm\ of\ both\ sides\\In(0.5) = In (e^{-0.001036t})\\-0.6931 = -0.001036t\\t = \frac{-0.6931}{-0.001036} \\t = 669.02 years\\\therefore t\frac{1}{2} \approx 669\ years$

Therefore the half-life is between 600 and 700 years

5 0

2 years ago

Solve for a<br><br> a² + 7a - 8 = 0

masya89 [10]

Answer:

a=-8

Step-by-step explanation:

5 0

2 years ago