The answer should be
f=1/5 x^2 + -2/5x
An applicable equation of a vertical parabola in vertex form is:
y-k = a(x-h)^2
Let x=2, y=4, h=-1 and k=-1, where (h,k) is the vertex. Then,
4-(-1) = a(2-[-1])^2, which becomes 5 = a(9). Therefore, a = 5/9, and the
equation of the parabola is
y+1 = (5/9)(x+1)
Answer:
what do u need help with
Step-by-step explanation:
Answer: the rate of speed for train A is 66 miles per hour.
Step-by-step explanation:
Let x represent the speed of train B.
2 trains leave the station at the same time. Train A is traveling 16 miles per hour slower than train B. This means that the speed of train A would be x - 16 miles per hour.
The two trains are 720 miles apart after 4 hours. It means that both trains traveled a total distance of 720 miles in 4 hours.
Distance = speed × time
Distance travelled by train A after 4 hours is
4(x - 16) = 4x - 64
Distance travelled by train B after 4 hours is
4 × x = 4x
Since the total distance travelled by both trains is 720 miles, then
4x - 64 + 4x = 720
8x = 720 - 64 = 656
x = 656/8 = 82 miles per hour
The speed of train A would be
82 - 16 = 66 miles per hour.
