Answer:
19
Step-by-step explanation:
In the first day the population will decrease to 1530, then 1500 the day 2, 1470 day 3, and so on ...
For decrease and get less than 1000 the mold population needs to be reduced in at least 560. The questions turns to be, how many days will it take to reduce the population in 560 spores?
If we divide 560 between 30 it will gives us the answer:
560/30 = 18.667
So, it is need to wait 19 days. In 18 days only 540 spores are reduced. In 19 days 570. We will say 19 days as we are looking (I guess) for an integer number.
Answer:
This is because it is easier this way.
You avoid the problem of putting an element in one set and then realizing that the element also belongs to another set, then you must erase something in order to put the element in both sets. Starting with the intersection allows you to know where will be each set in the diagram, and in this way, the diagram should end up being more readable or "clean".
This may seem small, but being "clean" when doing math, will allow you to have an easier time dealing with a lot of problems. And also will be easier for other people when reading your equations and such.
IF:
|1/2.x -2/3.y = 7 and
|a.x - 8.y = -1
have no solution, that means these 2 linear equations ARE PARALLEL (since they can never meet). Reminder: 2 equations are parallel if they have the same coefficient , so let write each of the equation in the normal form:
a)1/2.x -2/3.y = 7→ -2/3.y = -1/2.x + 7 → y = 3/4.x - 21/2
b) a.x - 8.y = -1 → - 8.y = -a.x - 1 → y= a/8.x + 1
a) and b) are // if (3/4) = (a/8), [the 2 coefficient OR the 2 slopes)
a/8 = 3/4 → a = 24/4 and a = 6 (Answer D)
Answer:
I was never good at this in math...
Sorry I didn't get any of that but I know that standard forms means numbers that count for something
