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4 years ago

PLEASE HELP! WILL UPVOTE!

1 answer:

6 0

Just "plug n chug" as my teacher would say. In other words, replace the letters with the values.

Choice A is (7,19) which means x = 7 and y = 19. Let's replace the x and y value with these numbers in both equations. If we get a true equation, then we found the answer.

2x-y = -5
2*7-19 = -5
14-19 = -5
-5 = -5 ... true
So that works. Let's try the other equation
x+3y = 22
7+3*19 = 22
7+57 = 22
64 = 22 ... false
So choice A is NOT the answer because of this. Let's try out choice B
2x-y = -5
2*4-9 = -5
-1 = -5 ... false
so B doesn't work either. How about C?
2x-y = -5
2*8-21 = -5
-5 = -5 ... that works
x+3y = 22
8+3*21 = 22
71 = 22 ... but this is false
So D has to be the answer. Let's check to confirm or not
2x-y = -5
2*1-7 = -5
-5 = -5 ... true
x+3y = 22
1+3*7 = 22
22 = 22 ... true
BOTH equations are true at the same time so (1,7) is definitely the final answer

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Help with questions, I don't care if you google it

frutty [35]

Question 1:

$7.488*10^{-8}$ ÷ $3.12*10^{2}$

= $\frac{7.488*10^{-8}}{3.12*10^{2}} = 2.4* 10^{-8-2} = 2.4* 10^{-10}$

Hence, the answer is A.

Question 2:

Mass = $2.8* 10^{-11}$ grams

New mass = $2.8 * 10^{-8}$ milligrams

Question 3:

$2.085*10^{6} = 2,085,000$

Hence, the answer is C.

3 0

3 years ago

What is the unit value of the 6 in 216?

eduard

The 6 is in the ones place the 1 is in the tens place and the 2 is in the hundreds place.

8 0

3 years ago

An experiment consists of rolling a single die and selecting a card from a standard deck. Use this information to answer the fol

Alexus [3.1K]

Answer:

1/160

Step-by-step explanation:

Assuming that you want to roll a 5 and then select the ace of hearts that would make this a sequence of events. In order to find the probability of this happening, you would need to multiply the probability of each of these events happening separately with one another.

Since there are a total of 6 possible outcomes when rolling a die (1,2,3,4,5,6) which rolling a 5 is only one of the options. Meaning that the probability of rolling a 5 is 1/5.

In a deck of cards, there are a total of 32 cards in the deck and only 1 of those cards is an ace of hearts. Meaning that the probability of getting the ace of hearts is 1/32. Now we simply multiply these two probabilities together to get the probability of the sequence.

1/5 * 1/32 = 1/160

4 0

3 years ago

Artemisia moves to a new house and she is "fifty-percent sure" that the phone number is 2537267. To verify this. she uses the ho

lana [24]

Answer:

My answer was wrong :/

Step-by-step explanation:

My answer was wrong :/

6 0

4 years ago

g Farmer Violet wants to enclose one 990 square foot rectangular area of land using fencing. One side will use special fencing c

saw5 [17]

Answer:

Sides of the rectangular area:

x = 30 f

y = 33 f

Step-by-step explanation:

Let´s call x and y the sides of the rectangular area

A = x*y = 990 y = 990/x

The function cost is:

C = Costs ( sides x) + costs ( sides y )

Cost of sides x = 12*x + 10x

Cost of sides y = 10*y + 10 *y = 2*10*y = 20*y

C = 12*x + 10*x + 20*y = 22*x + 20*y

The function cost as function of x is:

C(x) = 22*x + 20*(990/y) = 22*x + 19800/x

Tacking derivative on both sides of the equation:

C´(x) = 22 + [ - 19800/x²]

C´(x) = 0 22 - 19800/x² = 0

Solving for x

22*x² - 19800 = 0

22x² = 19800

x² = 19800/22 = 900

x₁,₂ = ± 30 We dismiss negative root ( we never have negative lenghts)

Then x = 30 f

And y = 990 / 30 y = 33

To see if x = 30 is a minimum for function C(x) we evaluate the second derivative.

C´´(x) = 2*x* 19800/x⁴

C´´ (x) = 39600/x³ so C´´ is always greater than 0 then C (x) has a minimum at x = 30

Sides of the rectangular area are:

x = 30

y = 33

6 0

3 years ago