One kind of bacteria in a laboratory culture triples every 30 minutes. Suppose the culture is started with 20 bacteria cells. How many bacteria will there be after two hours?​

2 hours = 4 * 30 minutes

30 * 3 = 90

90 * 3 = 270

270 * 3 = 810

810 * 3 = 2430

So after 2 hours you will have 2430 bacteria cells.

Step-by-step explanation:

answer: i would say b

step-by-step explanation:

with the way the question is worded, i believe b is the answer

the cost of the apple depends on the weight

let's cover over the formula of the vertex:

y = a(x – h)^2 + k

in this formula, (h,k) are the vertex, always remember that the positive or negative value of the vertex is based on the sign it has.

for example, if the vertex is -3,-6 then both the x and y value would have the positive sign attached to it and if it were a positive x and y value, then a negative sign would be attached to it.

with that being said, for our problem the x value is a positive one so we are looking for a number with a negative sign next to it, in this case the first and second choice.

however, for the first answer choice it isn't quite part of the formula so we know that the answer choice correctly displays the x value.

to confirm, we can see if the -1 fits correctly with the second answer choice, and as mentioned above a negative number will have a positive sign attached to it. so, for our problem we can see that -1 has been changed to +1, so we can confirm that the second answer choice is correct.

hence, our final answer is y=(x - 1)^2 + 1