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2 years ago

Which expression is equivalent to (7-8) (78)?

Mathematics

1 answer:

Gre4nikov [31]2 years ago

8 0

-78

Step-by-step explanation:

(7-8)(78)

(-1)(78)=-78

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A bacterial culture starts with 500 bacteria and doubles in size every half-hour.

tekilochka [14]

Answer:

a). 32000

b). $T_{t}=500\times 4^{t}$

c). 1259

Step-by-step explanation:

Growth of a bacteria is always exponential. Therefore, population of the bacteria is represented by the the geometric sequence.

Sum of the bacterial population after t hours will be represented by

$T_{n}=ar^{n}$

Where a = population at the start

r = ratio with the population is growing

n = time or duration of the growth in one hour

a). Population of 500 bacteria gets doubled after half an hour.

Or gets 4 times after an hour

This sequence will have a common ratio r = 4

and initial population a = 500

Therefore, population of the bacteria after 3 hours will be

$T_{3}=500\times 4^{3}$

$T_{3}=32000$

b). After t hours number of bacteria will be represented by

$T_{t}=500\times 4^{t}$

c). We have to calculate the population after 40 minutes.

That means duration 't' = 40 minutes of $\frac{2}{3}$ hours

By the formula,

$T_{\frac{2}{3}}=500\times 4^{\frac{2}{3}}$

$T_{\frac{2}{3}}=1259.92$ ≈ 1259

Therefore, number of bacteria after 40 minutes will be 1259.

8 0

2 years ago

Read 2 more answers

My Algebra 1 teacher is teaching us slope. Any tips and tricks?

Nuetrik [128]

Slope Intercept form is: y=mx+b
Standard Form is: Ax+By=C
Point Slope form is: y-y1=m(x-x1)

6 0

2 years ago

A car is travelling at exactly 6 miles per hour and accelerates at a constant rate to exactly 65 miles per hour.

vichka [17]

Answer:

$14878.04878miles/hours^2$

Step-by-step explanation:

Let's find a solution by understanding the following:

The acceleration rate is defined as the change of velocity within a time interval, which can be written as:

$A=(Vf-Vi)/T$ where:

A=acceleration rate

Vf=final velocity

Vi=initial velocity

T=time required for passing from Vi to Vf.

Using the problem's data we have:

Vf=65miles/hour

Vi=6miles/hour

T=14.8seconds

Using the acceleration rate equation we have:

$A=(65miles/hour - 6miles/hour)/14.8seconds$ , but look that velocities use 'hours' unit while 'T' uses 'seconds'.

So we need to transform 14.8seconds into Xhours, as follows:

$X=(14.8seconds)*(1hours/60minutes)*(1minute/60seconds)$

$X=0.0041hours$

Using X=0.0041hours in the previous equation instead of 14.8seconds we have:

$A=(65miles/hour - 6miles/hour)/0.0041hours$

$A=(61miles/hour)/0.0041hours$

$A=(61miles)/(hour*0.0041hours)$

$A=61miles/0.0041hours^2$

$A=14878.04878miles/hours^2$

In conclusion, the acceleration rate is $14878.04878miles/hours^2$

7 0

2 years ago

at right is graph of this situation predict how the line would change to present the average cost of gas in dicember of 2005 whe

Lina20 [59]

The average cost represents the slope of the line of the graph.
Increasing the slope of the graph increases the steepness of the line.
Therefore, increasing the average cost of gas from $1.50 to $2.20 will increases the steepness of the line. (i.e. the line becomes closer to the vertical line).

8 0

2 years ago

1.905 rounded to the nearest tenth

Tema [17]

1.905 rounded to the nearest tenth is 1.9

4 0

3 years ago