C..................................................
The given options are:
- (A)x+y = 20
- (B)7 apps and 14 movies
- (C)x-y= 20
- (D)y=-x+ 20
- (E)8 apps and 12 movies
- (F)xy= 20
Answer:
- (A)x+y = 20
- (D)y=-x+ 20
- (E)8 apps and 12 movies
Step-by-step explanation:
If Elizabeth has a combined total of 20 apps and movies.
Where:
Number of apps=x
Number of Movies =y
Then:
Their total,
If we subtract x from both sides
x+y-x=-x+20
In Option E
8 apps and 12 movies add up to 20. Therefore, this could also apply.
9/3 =3
(X+7)^2/ (x+7) = x+7
1/x-1
3(x+7)/x-1
3x+21/x-1
Answer:
13.2 minutes or 13 minutes 12 seconds.
Step-by-step explanation:
1. Count how much water drains the first pump every minute. Let the volume of pool be D. Every minute first pump drains D/11 water.
2. Working together(6 minutes) First pump drains 6D/11 water, hence the second pump drains 5D/11 water.
3.Count how much water drains second pump per minute -> (5D/11)/6= 5D/66
4. It takes the second pump 66 minutes to drain pool 5 times, thus it takes 13.2(66/5) minutes to drain the pool, which is 13 minutes 12 seconds.