Question

The number of bacteria in an experiment can be represented by f(x) = 4*,

where x represents the number of hours.
What is x when fx) = 64?
O
A. x = 3; In the 3rd hour there will be 64 bacteria.
. X = 16; In the 16th hour there will be 64 bacteria.
O
c. x = 60; In the 60th hour there will be 64 bacteria.
O
D. X= 4; In the 4th hour there will be 64 bacteria.​

Answer 1

The correct option is A.

Step-by-step explanation:

The number of bacteria in an experiment can be represented by an exponential function

`f(x)=4^x`

where, x represents the number of hours.

We need to find the value of x when f(x)=64.

Substitute f(x)=64 in the given function.

`64=4^x`

It can be rewritten as

`4^3=4^x`

On comparing both sides by get

`3=x`

The value of x is 3.

Since f(3)=64 it means the population of bacteria is 64 in 3rd hour.

Therefore the correct option is A.

Answer 2

The number of bacteria is represented with a function,

`f(x)=4^x`

The practise says
`f(x)=64` therefore,

`64=4^x`

We can rewrite this,

`4^x=4^3`

If bases are equal then exponents are too, from here the solution emerges,

`\boxed{x=3}`

The answer is A.

Hope this helps.

r3t40