Answer:
It isn't necessary but having a positive coefficient for 
makes things like completing the square and factoring easier.
Answer:
47/10 = 4 7/10
Step-by-step explanation:
3 2/5 + 1 3/10
1. Write mixed numbers as improper fractions:
17/5 + 13/10
2. Write equivalent fractions with a common denominator:
34/10 + 13/10
3. Add the numerators over the common denominator.
47/10
4. Simplify.
4 7/10
Answer:First you have to add all of the shirts together, which gives you: 40
Since 15 of those are black, then you need to put those 15 over the total number of 40, making it 15/40.
Then you must simplify by the highest number that will go into both, and since that number is 5, it will then go into 15 three times and it will go into 40 eight times.
That leaves you with the answer of: 3/8
Answer:
System of equations:
20x + 30y = 650
x + y = 25
Time underwater = 10 hours
Time at the surface = 15 hours
Step-by-step explanation:
Let x = time underwater at 20 km/h.
Let y = time on the surface at 30 km/h.
speed = distance/time
distance = speed * time
distance underwater: 20x
distance on the surface: 30y
total distance: 650
20x + 30y = 650
total time: x + y
total time: 25
x + y = 25
20x + 30y = 650
x + y = 25
20x + 30y = 650
-20x - 20y = -500
--------------------------------
10y = 150
y = 15
x + y = 25
x + 15 = 25
x = 10
Srry idk the ans for this que
