I need help, please anyone!

Lilit [14]

5-(8v+5) = -4(1+3v)
5-8v-5 = -4 - 12v
-8v = -4 - 12v
4v = -4
v = -1

8 0

3 years ago

Rita has a debit of $324 how much money does she need so that she doesn't do anything but left with no additional money?

Ilya [14]

Rita has a debit of $324, or she owes 324. Her balance is -324

The additive inverse property states that to find 0, add the inverse of the number

(-324) + (324) = 0

Rita would need to deposit $324.

hope this helps

8 0

4 years ago

1. Sarah's age is twice that of her sister. When you add Sarah's age to her sister's age, you get 33. How old is

Semmy [17]

Answer:

x+2x=33

3x=33

x=11

Sara's sisiter is 11

Sarah is (11 times 2) 22

6 0

4 years ago

Read 2 more answers

A very large tank initially contains 100L of pure water. Starting at time t = 0 a solution with a salt concentration of 0.8kg/L

Scorpion4ik [409]

Answer:

1. $\dfrac{dy}{dt}=4-\dfrac{3y(t)}{100+2t}$

2. $y(40) = 110.873 \ kg$

Step-by-step explanation:

Given that:

A very large tank initially contains 100 L of pure water.

Starting at time t = 0 a solution with a salt concentration of 0.8kg/L is added at a rate of 5L/min.

. The solution is kept thoroughly mixed and is drained from the tank at a rate of 3L/min.

As 5L/min is entering and 3L/min is drained out, there is a 2L increase per minute. Therefore, the amount of water at any given time t = (100 +2t) L

t = (50 + t ) L

Since it is given that we should consider y(t) to be the amount of salt (in kilograms) in the tank after t minutes.

Then , the differential equation that y satisfies can be computed as follows:

$\dfrac{dy}{dt}=rate_{in} - rate_{out}$

$\dfrac{dy}{dt}=(0.8)(5) -\dfrac{y(t)}{100+2t} \times3$

$\dfrac{dy}{dt}=(0.8)(5) -\dfrac{3y}{100+2t}$

$\dfrac{dy}{dt}=4-\dfrac{3y(t)}{100+2t}$

How much salt is in the tank after 40 minutes?

So,

suppose : $e^{\int \dfrac{3}{100+2t} \ dt} = (t+50)^{3/2}$

Then ,

$( t + 50)^{3/2} y' + \dfrac{3}{2}(t+50)^{1/2} y = 4(t+50)^{3/2}$

$( t + 50)^{1.5} y' + \dfrac{3}{2}(t+50)^{0.5} y = 4(t+50)^{3/2}$

$[y\ (t + 50)^{1.5}]' = 4(t+ 50)^{1.5}$

Taking the integral on both sides; we have:

$[y(t + 50)^{1.5}] = 1.6 (t + 50)^{2.5} + C$

$y = 1.6 (t+50)+C(t+50)^{-1.5}$

$y(0) = 0 = 1.6(0+50) + C ( 0 + 50)^{-1.5}$

$0 = 1.6(50) + C ( 50)^{-1.5}$

$C= -1.6(50)^{2.5}$

$y(40) = 1.6 (40 + 50)^1 - 1.6 (50)^{2.5}(50+40)^{-1.5}$

$y(40) = 144 - 1.6 \times 17677.66953 (90)^{-1.5}$

$y(40) = 144 - 1.6 \times 17677.66953 \times 0.001171213948$

$y(40) = 144 - 33.12693299$

$y(40) = 110.873 \ kg$

6 0

4 years ago

you borrow $500 from your parents to buy a new computer. your parents charge yoa 3% simple interest and give you two years to re

hammer [34]

A) 3% of $500 is 500×0.03=$15. This means that for one year, the interest added is $15. As we are dealing with simple interest, this amount will be added on the loan each year, and doesn't change. Therefore, over 2 years, the amount of interest you pay on the loan is 15×2=$30
b) You now need to add the extra interest to the original loan. So, 500+30=$530

3 0

4 years ago