All categories

3 years ago

the area of a rectangle is 99ft^2,and the L is 7ft more than twice the width. find the dimension of the rectangle.

1 answer:

3 0

A = L * W
A = 99
L = 2W + 7

99 = W(2W + 7)
99 = 2W^2 + 7W
-2W^2 - 7W + 99 = 0
(-2W + 11)(W + 9) = 0

-2W + 11 = 0
-2W = -11
W = -11/-2
W = 5.5

W + 9 = 0
W = -9 .....not this one because it is negative

so the width (W) = 5.5ft <====
L = 2W + 7 .....2(5.5) + 7 = 18 ft is the length (L) <==

You might be interested in

Which value of x is in the domain of f(x) = square root of x-5

Gelneren [198K]

The answer is A. x= 5

3 0

3 years ago

What is the slope of (5,8) (18,18)

Anettt [7]

Answer:

10/13

Step-by-step explanation:

Y1-Y2 / X1-X2

18-8 / 18-5

18-8 = 10

18-5 = 13

6 0

3 years ago

A 99% confidence interval for the difference between two proportions was estimated at 0.11, 0.39. Based on this, we can conclude

sladkih [1.3K]

Answer:

$\hat p_1 -\hat p_2 \pm z_{\alpha/2} SE$

And for this case the confidence interval is given by:

$0.11 \leq p_1 -p_2 \leq 0.39$

Since the confidenc einterval not contains the value 0 we can conclude that we have significant difference between the two population proportion of interest 1% of significance given. So then we can't conclude that the two proportions are equal

Step-by-step explanation:

Let p1 and p2 the population proportions of interest and let $\hat p_1$ and $\hat p_2$ the estimators for the proportions we know that the confidence interval for the difference of proportions is given by this formula:

$\hat p_1 -\hat p_2 \pm z_{\alpha/2} SE$

And for this case the confidence interval is given by:

$0.11 \leq p_1 -p_2 \leq 0.39$

Since the confidence interval not contains the value 0 we can conclude that we have significant difference between the two population proportion of interest 1% of significance given. So then we can't conclude that the two proportions are equal

4 0

3 years ago

The mass of a bacteria culture doubles every four days. If the initial sample is 5mg: a) how much will you have after one week (

maks197457 [2]

Answer:

a) 16.82 mg

b) 24 days

Step-by-step explanation:

Formula for exponential growth is given as:

$A=A_0b^{\frac{t}{c}}$

Where A is the final population

$A_0$ is the initial population

b is the growth factor

c is the time taken for the growth 'b'

t is the amount of time

Here, We are given the following:

$A_0$ = 5 mg

b = 2 (Given because it doubles)

c = 4 days

a) A = ?

Using the formula:

$A=5 \times 2^{\frac{7}{4}}\\\Rightarrow A=5 \times 2^{1.75} \\\Rightarrow A = \bold{16.82\ mg}$

b) Given

A = 320 mg

t = ?

Using the above formula again:

$320 = 5 \times 2^{\frac{t}{4}}\\\Rightarrow \dfrac{320} 5= 2^{\frac{t}{4}}\\\Rightarrow 2^{\frac{t}{4}} = 64\\\Rightarrow 2^{\frac{t}{4}} = 2^6\\\Rightarrow \dfrac{t}{4} = 6\\\Rightarrow t = 6 \times 4\\\Rightarrow \bold{t = 24\ days}$

So, the answers are:

a) 16.82 mg

b) 24 days

6 0

3 years ago

What is the solution to the equation? <br><br><br>5(n - 1/10) = 1/2

stira [4]

Answer:

i have made it in picture hope it help

6 0

2 years ago