Answer: There would be 12,000 bacteria 8 hours after the initial infection.
Step-by-step explanation: You start with 25 cells and if they divide every 15 minutes, 25 multiplied by 15 gets you 375 cells every quarter of an hour. Then if you multiply that by the 32 quarter hours, you get 12,000 cells. To check that you can also multiply 25 by 15, still 375, then 375 by 4 for each quarter of the hour, then that gets you 1,500 cells every hour. If you multiply that by 8 for the 8 hours they have time to divide, you still get 12,000 cells.
I hope this helps!
12x > 9(2x-3)-15
distribute the 9
12x > 18x-27 -15
combine like terms on the right side
12x > 18x-42
subtract 18x from both sides
-6x > -42
divide both sides by -6
x = -42 / -6 = 7
x >7
Answer:
- 525 = (w+4)(w)
- 21 ft by 25 ft
Step-by-step explanation:
Let w represent the width of the floor. Then the length of the floor is (w+4) and its area is ...
A = LW
525 = (w+4)(w)
w^2 +4w -525 = 0
(w -21)(w +25) = 0 . . . . factor the above
Solutions are ...
w = 21, w = -25
We are interested in the positive solution: w = 21.
The floor is 21 feet wide and 25 feet long.
_____
<em>Alternate solution</em>
Sometimes, when the factors aren't obvious, it works well to write an equation for the average of the dimensions. Here, we can represent that with x, and use (x-2) for the width, and (x+2) for the length. Then we have ...
525 = (x-2)(x+2) = x^2 -4
529 = x^2
√529 = 23 = x
Then w=23 -2 = 21, and the length is w+4 = 25.
Answer:
2 stars and 3 points
Step-by-step explanation:
8+2=10
10+4=14
14+6=20
the value increases by 2 each time.
12+3=15
15+6=21
21+9=30
this value is based on multiples of three.
Good luck
Answer:
I hope this helps
Step-by-step explanation:
-3 1/8
