A culture of a certain bacteria doubles every hour. At 9:00 a.m, there were already 120 bacteria. Which equation represents the number of bacteria, n, at 8:00 a.m? How many bacteria were there?(1 point)
Responses
2n=120; at 8:00 a.m., there were 60 bacteria.
2 n equals 120 ; at 8:00 a.m., there were 60 bacteria.
n/2=120; at 8:00 a.m., there were 60 bacteria.
Start Fraction n over 2 End Fraction equals 120 ; at 8:00 a.m., there were 60 bacteria.
2n=120; at 8:00 a.m., there were 240 bacteria.
2 n equals 120 ; at 8:00 a.m., there were 240 bacteria.
n.2=120; at 8:00 a.m., there were 240 bacter
2n = 120; at 8:00 a.m., there were 60 bacteria.
The correct equation that represents the number of bacteria, n, at 8:00 a.m. is 2n = 120.
To solve for n, divide both sides of the equation by 2:
n = 120/2
n = 60
Therefore, at 8:00 a.m., there were 60 bacteria.
The correct equation that represents the number of bacteria, n, at 8:00 a.m. is 2n=120. Now, let's explain how we get to this equation.
We know that the bacteria doubles every hour. So, from 8:00 a.m. to 9:00 a.m., which is a span of 1 hour, the number of bacteria doubles. If at 9:00 a.m. there were 120 bacteria, then at 8:00 a.m., which is one hour earlier, there would be half that number.
Therefore, we can represent the number of bacteria at 8:00 a.m. as n, and we can write the equation as 2n=120, where n is half of 120.
Solving this equation, we divide both sides by 2 to isolate n:
2n/2 = 120/2
n = 60
So, at 8:00 a.m. there were 60 bacteria. Therefore, the correct answer is "2n=120; at 8:00 a.m., there were 60 bacteria."