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
Answer:
7
Step-by-step explanation:
Answer: -29.3
Step-by-step explanation: -7y + 2x
-7(-6.3) + 2(-7.4) = -29.3
Answer:
(a) 64 days
(b) 2 phones calls
Step-by-step explanation:
Answer:
A dress originally costs $120
Step-by-step explanation:
To find the original cost of the dress, we will follow the steps below;
let x represent the original cost of the dress
75% of x = $90
× x = $90
= $90
MULTIPLY both-side of the equation by 100
× 100 = $90×100
At the right-hand side of the equation, 100 will cancel out 100, leaving us with just 75x
75x = $9000
DIVIDE both-side of the equation by 75
75x/75 = $9000/75
At the left-hand side of the equation 75 will cancel-out 75 leaving us with just x
x= $9000/75
x = $120
A dress originally costs $120
