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3 years ago

Omar’s classroom has 2 closets. Each closet has 3 shelves. There are 5 backpacks on each shelf. How many backs are there in all

Mathematics

1 answer:

almond37 [142]3 years ago

5 0

I believe there are 35 backpacks in all. 2 closets have 6 shelves all together. Then 6*5=35.

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Answer for brainlist and extra points ☀️

tia_tia [17]

Answer:x+2y-12=0

Step-by-step explanation:

3x+6y=36

-36. -36

3x+6y-36=0

Divide by 3 to get

X+2x-12=0

8 0

2 years ago

Initially a tank contains 10 liters of pure water. Brine of unknown (but constant) concentration of salt is flowing in at 1 lite

zhenek [66]

Answer:

Therefore the concentration of salt in the incoming brine is 1.73 g/L.

Step-by-step explanation:

Here the amount of incoming and outgoing of water are equal. Then the amount of water in the tank remain same = 10 liters.

Let the concentration of salt be a gram/L

Let the amount salt in the tank at any time t be Q(t).

$\frac{dQ}{dt} =\textrm {incoming rate - outgoing rate}$

Incoming rate = (a g/L)×(1 L/min)

=a g/min

The concentration of salt in the tank at any time t is = $\frac{Q(t)}{10}$ g/L

Outgoing rate = $(\frac{Q(t)}{10} g/L)(1 L/ min)$ $\frac{Q(t)}{10} g/min$

$\frac{dQ}{dt} = a- \frac{Q(t)}{10}$

$\Rightarrow \frac{dQ}{10a-Q(t)} =\frac{1}{10} dt$

Integrating both sides

$\Rightarrow \int \frac{dQ}{10a-Q(t)} =\int\frac{1}{10} dt$

$\Rightarrow -log|10a-Q(t)|=\frac{1}{10} t +c$ [ where c arbitrary constant]

Initial condition when t= 20 , Q(t)= 15 gram

$\Rightarrow -log|10a-15|=\frac{1}{10}\times 20 +c$

$\Rightarrow -log|10a-15|-2=c$

Therefore ,

$-log|10a-Q(t)|=\frac{1}{10} t -log|10a-15|-2$ .......(1)

In the starting time t=0 and Q(t)=0

Putting t=0 and Q(t)=0 in equation (1) we get

$- log|10a|= -log|10a-15| -2$

$\Rightarrow- log|10a|+log|10a-15|= -2$

$\Rightarrow log|\frac{10a-15}{10a}|= -2$

$\Rightarrow |\frac{10a-15}{10a}|=e ^{-2}$

$\Rightarrow 1-\frac{15}{10a} =e^{-2}$

$\Rightarrow \frac{15}{10a} =1-e^{-2}$

$\Rightarrow \frac{3}{2a} =1-e^{-2}$

$\Rightarrow2a= \frac{3}{1-e^{-2}}$

$\Rightarrow a = 1.73$

Therefore the concentration of salt in the incoming brine is 1.73 g/L

8 0

3 years ago

700grams must be mixed in 100ml of water, and 0.09 grams of salt added. A cook however has 325 grams. what is the quantity of wa

jek_recluse [69]

57 grams water and 0.003grams salt

3 0

3 years ago

Samantha had $15.She spends $2.25 on admission to the ice skating rink, $2.15 to rent ice skates and $1.35 each for 2 hot chocol

jolli1 [7]

Answer: $7.90

Step-by-step explanation:

When we see how much she spent on the total cost of renting skates, getting in, and getting hot chocolate, we can see that she is going to subtract all of that from the total cost.

$15.00 - 2.25 = 12.75

12.75 - 2.15 = 10.60

10.60 - 1.35 = 9.25

9.25 - 1.35 = 7.90 remaining

We know that she payed 2.25 to get in, 2.15 for skate rental, and 1.35 for each hot chocolate she purchased which in this case is 2. We need to subtract all of this from 15 and get the final answer

7 0

2 years ago

Bennett and Jarrett are both saving money to buy a new dirtbike’s

lions [1.4K]

THERES NO MATH SO I CANT ANSWER YOUR QUESTION

8 0

2 years ago