All categories

3 years ago

How do you find the solution

Mathematics

1 answer:

aleksandr82 [10.1K]3 years ago

4 0

Given that there were 30 bacteria present originally.
a=30
Also given that the number doubles every one hour.
After one hour the count =2×30=60
Since the count doubles every hour it forms a G.P. with r=2
a,ar,ar2........
The count at the end of 2nd hour=ar^2=30×2^2=120
The count at the end of 4th hour=ar^4=30×2^4=480
The count at the end of 8th hour=ar^8n=30×2^8=7680
etc.
The count at the end of n^th hour=ar^n=30×2^n

Also, the equation y=30*(2)^8/1 give the same result y= 7680

You might be interested in

Graphs that represent situations that may not have numerical values are Called?

vovikov84 [41]

Qualitative graphs.

7 0

2 years ago

Please explain with working!!! Find the set of values of x that satisfy the inequality 9x^2-15x<6

Oksi-84 [34.3K]

Answer:

$-1/3$

Step-by-step explanation:

When solving a quadratic inequality, first solve it normally like you would for a normal quadratic equation. We have:

$9x^2-15x$

Ignore the less than sign and replace it with an equal sign and solve the quadratic for its zeros:

$9x^2-15x=6$

Subtract 6 from both sides:

$9x^2-15x-6=0$

Divide everything by 3:

$3x^2-5x-2=0$

Factor. Find two numbers that equal (3)(-2)=-6 that add up to -5.

-6 and 1 works. Thus:

$3x^2-6x+x-2=0\\3x(x-2)+1(x-2)=0\\(3x+1)(x-2)=0$

Find the x using the Zero Product Property:

$3x+1=0 \text{ or }x-2=0\\x=-1/3\text{ or }x=2$

Now, we need to replace the equal signs with symbols again. To do so, we need to test which symbol to place. Let's do the first zero first.

So, the first zero is:

$x=-1/3$

Assume that the correct symbol is >. Thus,

$x>-1/3$

Now, pick any number that is greater than -1/3. I'll pick 0 since it's the easiest. Now, plug 0 back into the very original inequality. If it works, then the sign is correct, if it doesn't, then simply use the opposite one. Therefore:

$9x^2-15x$

0 is indeed less than six, so our first correct solution is:

$x>-1/3$

For the second one, do the same thing. We have:

$x=2$

Assume that the correct symbol is <. Thus:

$x$

Again, pick any number less than 2. I'm going to use 0. Plug 0 back into the original equation

$9x^2-15x$

Again, this is correct. Therefore, x<2 is also the correct inequality.

So together, we have:

$x>-1/3 \text{ and } x$

Together, we can write them as:

$-1/3$

(Note that we don't need to worry about the "or equal to" part since the original inequality didn't have it.)

6 0

3 years ago

What is x cubed in standard form

Gelneren [198K]

Answer:

x^3

Step-by-step explanation:

It stays the same.

Hope this helps.

3 0

3 years ago

How do you multiply mixed numbers with fractions

Vaselesa [24]

Answer:

Step-by-step explanation:

You first turn the mixed number into an improper fraction by mutliplying the denominator by the whole number then adding the numerator to the product. Make sure to keep the denominator the same and just put the sum as the numerator. Then, you multiply the fractions and simplify your answer! Hope this helped!

4 0

3 years ago

Read 2 more answers

Form the quadratic equation whose one root is 2 + 2^(1/2)

Oksanka [162]

9514 1404 393

Answer:

x^2 -4x +2 = 0

Step-by-step explanation:

The other root is the conjugate of the given one, so is 2-√2. The quadratic equation in factored form is then ...

(x -2-√2)(x -2+√2) = 0

Expanding this, we get ...

(x -2)^2 -(√2)^2 = 0

x^2 -4x +4 -2 = 0

x^2 -4x +2 = 0 . . . . the equation you're looking for

4 0

3 years ago