Answer:
Step-by-step explanation:
s(1-30/100)=420
s(100-30)/100=420
s(70/100)=420
s(7/10)=420
7s=4200
s=600
Answer:
V1 = 60 km/h
V2 = 40 Km/h
Step-by-step explanation:
The speed of an object is defined as
Speed = distance / time
Let
V1 be the speed of the faster car
V2 be the speed of the other car
t1 the time it took for the first car to arrive
t2 the time it took for the second car to arrive
d1 the distance traveled by first car
d2 the distance traveled by second car
We know thanks to the problem that
V1 = V2 + 20 Km/h
t1 = t2 - 1 hour
d1 = d2 = 120 Km
d1 = V1 * t1
d2 = V2* t2
V1 * t1 = V2* t2
V1* t1 = (V1 -20)*(t1 +1)
The system of equations
(V1 -20)*(t1 +1) = 120
V1 * t1 = 120
120 + (120/t1) -20*t1 = 140
(120/t1) -20*t1 = 20
Which gives,
t1 = 2
This means
V1 = 60 km/h
V2 = V1 - 20 Km/h = 40 Km/h
No, because
60/3 = 20
90/6= 15
Both of the answers aren’t equivalent.
Answer:
B
Step-by-step explanation:
because we just multiply the bottom equation by - and we eliminate 7y. now we have -2x=-10 to get x we divide -10 by -2 and get the answer
