Answer:
Step-by-step explanation:
Any number equal to or greater than 20 is a solution. 22 would be a solution.
Answer:
x = 30
Step-by-step explanation:
2x + 90° + x = 180°
3x + 90° = 180°
3x = 90°
x = 90/3
x = 30
Answer: 
Step-by-step explanation:
This is a multiplication problem. You are multiplying
by 4. This also means 4 divided by 3. They are both the same.
16pi
Step-by-step explanation:
pi x r² = ans ÷ 4 = Answer for area
Pi×8²=64pi ÷ 4 = 16pi
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