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.
Answer:
b
Step-by-step explanation:
Triangular sequence = n(n + 1)/2
If 630 is a triangular number, then:
n(n + 1)/2 = 630
Then n should be a positive whole number if 630 is a triangular number.
n(n + 1)/2 = 630
n(n + 1) = 2*630
n(n + 1) = 1260
n² + n = 1260
n² + n - 1260 = 0
By trial an error note that 1260 = 35 * 36
n² + n - 1260 = 0
Replace n with 36n - 35n
n² + 36n - 35n - 1260 = 0
n(n + 36) - 35(n + 36) = 0
(n + 36)(n - 35) = 0
n + 36 = 0 or n - 35 = 0
n = 0 - 36, or n = 0 + 35
n = -36, or 35
n can not be negative.
n = 35 is valid.
Since n is a positive whole number, that means 630 is a triangular number.
So the answer is True.
No this data set is not a function because two points have x coordinates of 4
Hope this helps
