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2 years ago

Pamela is 6 years younger than Jiri. The sum of their ages is 78 . What is Jiri's age?

1 answer:

6 0

Let’s make

P = Pamela
J = Jiri

J - 6 = P

P + J = 78

We can replace P with J - 6 because they are the same thing.

J - 6 + J = 78

2J - 6 = 78

2J = 84

J = 42

Jiri is 42 years old.

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What are the parameters of linear functions

xz_007 [3.2K]

Answer:

Algebraically, linear functions are a two parameter family. The parameter a is called the function's y-intercept and the parameter b is called the slope. Together, they completely determine a linear function's input-output behavior. Notice that f(0) = a : The y-intercept is the output when the input is 0.

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3 years ago

A circus acrobat is shot out of a cannon. The equation for the acrobat's pathway can be modeled by h= -16t^2+25. How long will i

Alex_Xolod [135]

For this we almost have the following equation:
$h = -16t ^ 2 + 25
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We must match the equation to zero:
$-16t ^ 2 + 25 = 0
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From here, we clear the value of t.
We have then:
$16t ^ 2 = 25

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We discard the negative root because we are looking for time:
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Answer:
it will take him to reach the ground about:
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3 years ago

Zoé is working two summer making $7 per hour babysitting and making $15 per hour clearing tables. In given week, She can make a

Leviafan [203]

Answer:

Zoe can clear tables for 7, 8 , 9 and 10 hours to meet her requirements.

Step-by-step explanation:

Here according to the question:

Earning per hour of Zoe from babysitting = $7 per hour

Earning per hour of Zoe from clearing tables = $15 per hour

Let us assume the number of hours Zoe babysits = m hours

Also, let us assume the number of hours Zoe clears table = n hours

Now,as given : She can make a maximum of 14 total hours

SO, the number of hours worked at ( Babysitting + Clearing Tables) ≤ 14

or, m + n ≤ 14 ....... (1)

Now, the total earning after working m hours babysitting

= m x ( Cost of babysitting per hour) = m ($7) = 7 m

And, the total earning after working n hours clearing tables

= n x ( Cost of clearing tables per hour) = n ($15) = 15 n

Now, total earning after worming both jobs = 7 m + 15 n

But, She can must earn at least $130.

⇔ 7 m + 15 n ≥ 130 ......... (2)

Now, given : Number of hours Zoe babysits = 4 hours

⇒ m = 4

So, putting the value of m = 4 in (1) , we get: n = 14 - 4 = 10

Also, putting m = 4, n = 10 in (2) , we get:

7 m + 15 n = 7 (4) + 15(10) = 28 + 150 = 178 > 130

Hence, (4,10) is the SOLUTION OF THE GIVEN SYSTEM.

now, m = 4, so, n can be 1, 2, 3, 4, 5, .... 9 (any of the values)

for, m = 4, n = 1: 7 m + 15 n = 28 + 15 = 43 ≯ 130

⇔ Equation (2) is not satisfied for (4,1)

Checking for all values of (m,n), we get:

The possible solutions are: (4 ,7) , (4,8) , (4,9) and (4, 10).

Hence, she can clear tables for 7, 8 , 9 and 10 hours to meet her requirements.

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4 years ago

Please show step by step of working out the value of r for which is A is aminimum and calculate the minimum surface area of the

almond37 [142]

Answer:

The minimum surface area of the container is 276.791 square units.

Step-by-step explanation:

Let be $A(r) = \pi\cdot r^{2} + \frac{1000}{r}$ , $\forall \,r \in \mathbb{R}$ , $r \geq 0$ . The first and second derivatives of such function are, respectively: