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3 years ago

One quarter of a certain number added to one eighth of the same number is 12. What is the number

Mathematics

1 answer:

alexdok [17]3 years ago

6 0

Answer:

Step-by-step explanation:

let the number be n , then

$\frac{1}{4}$ n + $\frac{1}{8}$ n = 12 ( multiply through by 8 to clear the fractions )

2n + n = 96

3n = 96 ( divide both sides by 3 )

n = 32

The number is 32

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. Evaluate ƒ(x) = 3x + 8 for x = 1. 3 5 11 –11

rodikova [14]

Answer:

Step-by-step explanation:

Replace the variable xx with −1-1 in the expression.

f(−1)=−3⋅−1+8f(-1)=-3⋅-1+8

Simplify the result.

Tap for fewer steps...

Multiply −3-3 by −1-1.

f(−1)=3+8f(-1)=3+8

Add 33 and 88.

f(−1)=11f(-1)=11

The final answer is 1111.

=11

I want brainless pleased

8 0

3 years ago

the tens digit of a two digit number is 5 greater the units digit. If you subtract double the reversed number from it, the resul

likoan [24]

Given:

The tens digit of a two digit number is 5 greater the units digit.

If you subtract double the reversed number from it, the result is a fourth of the original number.

To find:

The original number.

Solution:

Let n be the two digit number and x be the unit digit. Then tens digit is (x+5) and the original number is:

$n=(x+5)\times 10+x\times 1$

$n=10x+50+x$

$n=11x+50$

Reversed number is:

$x\times 10+(x+5)\times 1=10x+x+5$

$x\times 10+(x+5)\times 1=11x+5$

If you subtract double the reversed number from it, the result is a fourth of the original number.

$11x+50-2(11x+5)=\dfrac{1}{4}(11x+50)$

$11x+50-22x-10=\dfrac{1}{4}(11x+50)$

$40-11x=\dfrac{1}{4}(11x+50)$

Multiply both sides by 4.

$160-44x=11x+50$

$160-50=11x+44x$

$110=55x$

Divide both sides by 55.

$\dfrac{110}{55}=x$

$2=x$

The unit digit is 2. So, the tens digit is $2+5=7$ .

Therefore, the original number is 72.

6 0

3 years ago

A chicken farmer also has cows for a total of 30 animals, and the animals have 66 legs in all. How many chickens does the farmer

hammer [34]

Answer:

27 chickens

Step-by-step explanation:

A chicken farmer also has cows for a total of 30 animals

Both animals have a total of 66 legs

Let a represent the number of chicken

Let b represent the number of cows

a + b= 30........equation 1

Since a chicken has only two legs and a cow has four leg then, the expression can be represented as

2a + 4b= 66........equation 2

From equation 1

a + b= 30

a = 30-b

Substitute 30-b for a in equation 2

2a + 4b= 66

2(30-b) + 4b= 66

60 - 2b + 4b= 66

60 + 2b= 66

2b= 66-60

2b= 6

b= 6/2

b= 3

Substitute 3 for b in equation 1

a + b = 30

a + 3=30

a= 30-3

a= 27

Hence the farmer has 27 chickens

5 0

4 years ago

The temperature, H, in degrees Celsius, of a cup of coffee placed on the kitchen counter is given by H = f(t), where t is in min

Deffense [45]

Answer:

f'(t) is negative

The unit is degC/min

At 35 minutes after the coffee was put on the counter, its temperature is 68 and will decrease by about 0.75 in the next 30 seconds.

Step-by-step explanation:

From the question we are told we are told that

The equation for the temperature of a cup of coffee place on a counter is

$H= f(t)$

Here t is the time in minutes the coffee was put on the counter

Generally f(t)' is the derivative of f(t) at it represents the change of the temperature of the cup of coffee with respect to time

Generally for the coffee placed on the counter after a couple of minutes the temperature will decrease hence f(t)' is negative

Generally the unit of the temperature is in degrees Celsius while that of time is in minutes

So the change in temperature with time f(35)' will be in degrees Celsius/minutes (i.e degC/min)

From the question we are told that

$|f(35)'| = 1.5$

i.e the rate of change of temperature after 35 minutes is 1.5

and

$|f(35)| = 68$

i.e the temperature of the cup of coffee after 35 minutes is 67 degC

Now after another t= 30 seconds = $\frac{30}{60}= 0.5 \ minutes$ the rate of change of the temperature of the cup of coffee is

$R = |f(35)'| * t$

=> $R = 1.5 * 0.5$

=> $R = 0.75$

At 35 minutes after the coffee was put on the counter, its temperature is 68 and will decrease by about 0.75 in the next 30 seconds.

5 0

3 years ago

Plz help with question

serious [3.7K]

Less than 90° = acute

more than 90° = obtuse

equal to 180° = straight

more than 360° = reflex

6 0

3 years ago

One quarter of a certain number added to one eighth of the same number is 12. What is the number​

One quarter of a certain number added to one eighth of the same number is 12. What is the number