I believe the answers to be 75+5x=y
Answer:
C
Step-by-step explanation:
The volume (V) of a sphere is calculated using the formula
V = 
πr³
If the radius is doubled, that is r = 2r , then
V = π (2r )³
(2r)³ = 8r³, thus the volume is multiplied by 8
Answer:
24/35 hours or 0.69 hours
Step-by-step explanation:
we know that
The speed is equal to divide the distance by the time
Let
x-----> distance traveled by John
(24-x) ----> distance traveled by Ramona
The time is equal to divide the distance by the speed
so
x/20=(24-x)/15
15x=20(24-x)
15x=480-20x
15x+20x=480
35x=480
x=480/35 miles
the time is equal to
t=x/20
t=480/(20*35)=24/35=0.69 hours
Answer:
10 hours
Step-by-step explanation:
(150/x) + 1.5 + (450/(x+15)) = 600/x
Multiply through by x(x + 15):
150(x + 15) + 1.5x(x + 15) + 450x = 600(x + 15)
150x + 2250 + 1.5x^2 + 22.5x + 450x = 600x + 9000
150x + 2250 + 1.5x^2 + 22.5x + 450x - 600x - 9000 = 0
1.5x^2 + 22.5x - 6750 = 0
x = (-22.5 +/- sqrt(22.5^2 - 4(1.5)(-6750))) / (2*1.5)
x = (-22.5 +/- sqrt(506.25 + 40500)) / 3
x = (-22.5 +/- sqrt(41006.25)) / 3
x = (-22.5 +/- 202.5) / 3
x = 180/3 or -225/3
x = 60 or -75
But a negative number doesn't make sense, so therefore x = 60, so the journey took 600/60 = 10 hours.
