Answer:
The actual speed of the car would be 57mph
Step-by-step explanation:
9. Given A = {1, 2, 3, 4, 5, 6, 7, 8, 9} and B = {2, 4, 6, 8}, what is A∪B?
PtichkaEL [24]
A union B is the set containing all elements in set A and set B there for A union B is the set {1 2 3 4 5 6 7 8 9}
You didn't post a file so I can't help you. Perhaps put a picture?
54
a rule I follow:
same signs positive,
different signs negative.
-9 * -3 = 27
27 + 27 = 54
S=d/t ⇒d=s*t
s=speed
d=distance
t=time
The first train :
d=x
x=70 miles/h*t ⇒ x=70t (1)
The second train
d=360 miles - x
360 miles - x=80 miles/h*t ⇒360-x=80t ⇒ x=360-80t (2)
therefore, with the equations (1) and (2) we have a systeme of equations:
x=70t
x=360-80t
we can solve this system of equations by equalization method.
70t=360-80t
70t+80t=360
150t=360
t=360/150=2.4 (≈2 hour 24 minutes)
Answer: the first train meet with the second train in 2 hour 24 minutes.
