A printer takes 5mins to print 90 copies of a repor. At this rate, how many copies of the same report can it print in 1/2 hours

Ami needs to divide these base-ten blocks into 5 equal groups.

Amanda [17]

Step-by-step explanation:

The model will contain 1 ten and 4 ones in each group.

5 0

3 years ago

What is the vertex of f(x)=x^2+6x+1 <br><br> Write your answer as an ordered pair without spaces

netineya [11]

Answer:

3

Step-by-step explanation:

5 0

3 years ago

**ANSWER ASAP WILL GIVE BRAINLIEST; QUESTIONS ARE IN PICTURE**

lord [1]

Answer:

below( hope this helps )

Step-by-step explanation:

2. No because we don't know if the triangles are right triangles.

3. unknown since there are no labels to what the triangle points are

6 0

3 years ago

A 1000-liter (L) tank contains 500 L of water with a salt concentration of 10 g/L. Water with a salt concentration of 50 g/L flo

djverab [1.8K]

Answer:

a) $y(t)=50000-49990e^{\frac{-2t}{25}}$

b) $31690.7 g/L$

Step-by-step explanation:

By definition, we have that the change rate of salt in the tank is $\frac{dy}{dt}=R_{i}-R_{o}$ , where $R_{i}$ is the rate of salt entering and $R_{o}$ is the rate of salt going outside.

Then we have, $R_{i}=80\frac{L}{min}*50\frac{g}{L}=4000\frac{g}{min}$ , and

$R_{o}=40\frac{L}{min}*\frac{y}{500} \frac{g}{L}=\frac{2y}{25}\frac{g}{min}$

So we obtain. $\frac{dy}{dt}=4000-\frac{2y}{25}$ , then

$\frac{dy}{dt}+\frac{2y}{25}=4000$ , and using the integrating factor $e^{\int {\frac{2}{25}} \, dt=e^{\frac{2t}{25}$ , therefore $(\frac{dy }{dt}+\frac{2y}{25}}=4000)e^{\frac{2t}{25}$ , we get $\frac{d}{dt}(y*e^{\frac{2t}{25}})= 4000 e^{\frac{2t}{25}$ , after integrating both sides $y*e^{\frac{2t}{25}}= 50000 e^{\frac{2t}{25}}+C$ , therefore $y(t)= 50000 +Ce^{\frac{-2t}{25}}$ , to find $C$ we know that the tank initially contains a salt concentration of 10 g/L, that means the initial conditions $y(0)=10$ , so $10= 50000+Ce^{\frac{-0*2}{25}}$

$10=50000+C\\C=10-50000=-49990$

Finally we can write an expression for the amount of salt in the tank at any time t, it is $y(t)=50000-49990e^{\frac{-2t}{25}}$

b) The tank will overflow due Rin>Rout, at a rate of $80 L/min-40L/min=40L/min$ , due we have 500 L to overflow $\frac{500L}{40L/min} =\frac{25}{2} min=t$ , so we can evualuate the expression of a) $y(25/2)=50000-49990e^{\frac{-2}{25}\frac{25}{2}}=50000-49990e^{-1}=31690.7$ , is the salt concentration when the tank overflows

4 0

3 years ago

Liam is making barbecue ribs over a fire. The internal temperature of the ribs when he starts cooking is 40°F. During each hour

Soloha48 [4]

Answer: You need to wait at least 6.4 hours to eat the ribs.

t ≥ 6.4 hours.

Step-by-step explanation:

The initial temperature is 40°F, and it increases by 25% each hour.

This means that during hour 0 the temperature is 40° F

after the first hour, at h = 1h we have an increase of 25%, this means that the new temperature is:

T = 40° F + 0.25*40° F = 1.25*40° F

after another hour we have another increase of 25%, the temperature now is:

T = (1.25*40° F) + 0.25*(1.25*40° F) = (40° F)*(1.25)^2

Now, we can model the temperature at the hour h as:

T(h) = (40°f)*1.25^h

now we want to find the number of hours needed to get the temperature equal to 165°F. which is the minimum temperature that the ribs need to reach in order to be safe to eaten.

So we have:

(40°f)*1.25^h = 165° F

1.25^h = 165/40 = 4.125

h = ln(4.125)/ln(1.25) = 6.4 hours.

then the inequality is:

t ≥ 6.4 hours.

4 0

3 years ago