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Neporo4naja [7]

3 years ago

12

manny says that if the expression was 12 divided 3^2 you would divide before simplifying 3^2, Is he right? Explain Please Answer

!!

1 answer:

Alona [7]3 years ago

8 0

Answer:

Wrong. PEMDAS exponents come before dividing

Step-by-step explanation:

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GCF of 4x^2y^2, 3xy^4, and 2xy^2

allsm [11]

The greatest common factor would be xy^2 because these are the only factors that they all have in common. The second term only has 1 x, so only 1 x is part of the gcf.

The 1st and 3rd terms each have y^2 therefore making it part of the gcf as well.

5 0

4 years ago

A tank contains 60 kg of salt and 1000 L of water. Pure water enters a tank at the rate 6 L/min. The solution is mixed and drain

MissTica

Answer:

(a) 60 kg; (b) 21.6 kg; (c) 0 kg/L

Step-by-step explanation:

(a) Initial amount of salt in tank

The tank initially contains 60 kg of salt.

(b) Amount of salt after 4.5 h

$\text{Let A = mass of salt after t min}\\\text{and }r_{i} = \text{rate of salt coming into tank}\\\text{and }r_{0} =\text{rate of salt going out of tank}$

(i) Set up an expression for the rate of change of salt concentration.

$\dfrac{\text{d}A}{\text{d}t} = r_{i} - r_{o}\\\\\text{The fresh water is entering with no salt, so}\\ r_{i} = 0\\r_{o} = \dfrac{\text{3 L}}{\text{1 min}} \times \dfrac {A\text{ kg}}{\text{1000 L}} =\dfrac{3A}{1000}\text{ kg/min}\\\\\dfrac{\text{d}A}{\text{d}t} = -0.003A \text{ kg/min}$

(ii) Integrate the expression

$\dfrac{\text{d}A}{\text{d}t} = -0.003A\\\\\dfrac{\text{d}A}{A} = -0.003\text{d}t\\\\\int \dfrac{\text{d}A}{A} = -\int 0.003\text{d}t\\\\\ln A = -0.003t + C$

(iii) Find the constant of integration

$\ln A = -0.003t + C\\\text{At t = 0, A = 60 kg/1000 L = 0.060 kg/L} \\\ln (0.060) = -0.003\times0 + C\\C = \ln(0.060)$

(iv) Solve for A as a function of time.

$\text{The integrated rate expression is}\\\ln A = -0.003t + \ln(0.060)\\\text{Solve for } A\\A = 0.060e^{-0.003t}$

(v) Calculate the amount of salt after 4.5 h

a. Convert hours to minutes

$\text{Time} = \text{4.5 h} \times \dfrac{\text{60 min}}{\text{1h}} = \text{270 min}$

b.Calculate the concentration

$A = 0.060e^{-0.003t} = 0.060e^{-0.003\times270} = 0.060e^{-0.81} = 0.060 \times 0.445 = \text{0.0267 kg/L}$

c. Calculate the volume

The tank has been filling at 6 L/min and draining at 3 L/min, so it is filling at a net rate of 3 L/min.

The volume added in 4.5 h is

$\text{Volume added} = \text{270 min} \times \dfrac{\text{3 L}}{\text{1 min}} = \text{810 L}$

Total volume in tank = 1000 L + 810 L = 1810 L

d. Calculate the mass of salt in the tank

$\text{Mass of salt in tank } = \text{1810 L} \times \dfrac{\text{0.0267 kg}}{\text{1 L}} = \textbf{21.6 kg}$

(c) Concentration at infinite time

$\text{As t $\longrightarrow \, -\infty,\, e^{-\infty} \longrightarrow \, 0$, so A $\longrightarrow \, 0$.}$

This makes sense, because the salt is continuously being flushed out by the fresh water coming in.

The graph below shows how the concentration of salt varies with time.

3 0

3 years ago

Is x = 6 a solution to the equation 5(x – 3) = x + 13?

deff fn [24]

Answer:

x=6 is not a solution

Step-by-step explanation:

We can substitute 6 as x to find out:

5(6-3)=6+13

first, because of PEMDAS we'll do 6-3

5(3)=6+13

multiply 5 by 3 and add 6 and 13

15=19

Since the statement is not true, that means that x=6 is not a solution

Hope this helps!

8 0

3 years ago

Determine the intercepts of the line. -5x+9y=-18

Stolb23 [73]

Answer:

x-intercept = (18/5,0)

y-intercept = (0,-2)

Step-by-step explanation:

I graphed it and found the intercepts

brainliest would be great

8 0

3 years ago

Claire and Lauren are sisters. Their mom gives them each a weekly allowance. Claire gets $5 more than Lauren a week. How much do

valkas [14]

We don't know the amount they get but the equation would be Claire 5 + a

5 0

3 years ago