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2 years ago

Evaluate 3x + 34 if x = 5.

Mathematics

2 answers:

Inessa [10]2 years ago

5 0

3x+34
3(5)+34
15+34
49
X=49

ki77a [65]2 years ago

3 0

Answer:

Step-by-step explanation:

3x + 34

x = 5

3 * 5 + 34

15 + 34

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What is the measure of F? 10

kolbaska11 [484]

Answer:

do you have a picture?

Step-by-step explanation:

I could use a picture

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3 years ago

Read 2 more answers

At the start of the week a bookshop had science and art books in the ratio 2:5. By the end of the week, 20% of each type of book

Anastaziya [24]

Let there be 2x science and 5x art books
science books sold = 2x × 0.2 = 0.4x 
science books unsold = 2x – 0.4x = 1.6x 

art books sold = 5x × 0.2 = x 
art books unsold = 5x – x = 4x 

total books unsold = 1.6x + 4x = 5.6x 
5.6x = 2240 
x = 400 

2x science = 800 
and 5x art books = 2000

5 0

3 years ago

Suppose that you are given a bag containing n unbiased coins. You are told that n-1 of these coins are normal, with heads on one

gladu [14]

Answer:

The (conditional) probability that the coin you chose is the fake coin is 2/(1 + n)

Step-by-step explanation:

Given

Total unbiased coin = n

Normal coins =n - 1

Fake = 1

The (conditional) probability that the coin you chose is the fake coin is represented by

P(Fake | Head)

And it's calculated as follows;

P(Fake | Head) = P(Fake, Head) ÷ P(Head) ----- (1)

Where P(Fake, Head) = P(Fake) * P(Head | Fake)

P(Fake) = 1/n --- because only one is fake

P(Head | Fake) = n/n because all coins (including the fake) have head

So, P(Fake, Head) = P(Fake) * P(Head | Fake) becomes

P(Fake, Head) = 1/n * n/n

P(Fake, Head) = 1/n

P(Head) is calculated by

P(Fake) * P(Head | Fake) + P(Normal) * P(Head | Normal)

P(Fake) * P(Head | Fake) = P(Fake, Head) = 1/n (as calculated above)

P(Normal) * P(Head | Normal) = ½ * (n - 1)/n ----- considering that the coin also has a tail with equal probability as that of the head.

Going back to (1)

P(Fake | Head) = P(Fake, Head) ÷ P(Head) becomes

P(Fake | Head) = (1/n) ÷ ((1/n) + (½(n-1)/n))

= (1/n) ÷ ((1/n) + (½(n-1)/n))

= (1/n) ÷ (1/n + (n - 1)/2n)

= (1/n) ÷ (2 + n - 1)/(2n)

= (1/n) ÷ (1 + n)/(2n)

= (1/n) * (2n)/(1 + n)

= 2/(1 + n)

Hence, the (conditional) probability that the coin you chose is the fake coin is 2/(1 + n)

5 0

3 years ago

A gallon of stain is enough to cover 200 square feet of decking. Bradley has two areas of decking he would like to cover with st

Pani-rosa [81]

The expression that we need to get is:

$N = \frac{(23)*(10.4) + (10.5)*(7.2)}{200}$

So the correct option is the second one.

<h3>Which expression gives the number of gallons of stain Bradley will need?</h3>

We know that 1 gallon is enough to cover 200 ft².

We have two rectangular areas, one of:

23 feet by 10.4 feet, and other of 10.5 feet by 7.2 feet.

Then the total area is:

A = (23 ft)*(10.4 ft) + (10.5ft)*(7.2 ft)

The number of gallons needed is given by the quotient between the area that we want to cover, and the area that covers one gallon, so the expression is:

$N = \frac{(23ft)*(10.4ft) + (10.5ft)*(7.2ft)}{200ft^2} \\\\N = \frac{(23)*(10.4) + (10.5)*(7.2)}{200}$