Answer:
The speed of the first car is 60 mph
Step-by-step explanation:
speed = distance/time
Solve the above equation for distance to get
distance = speed * time
or simply
d = st
Now we use this formula for distance to write an equation for each car.
Let s = speed of second car
Then since the speed of the first car is 10 mph faster, the first car's speed is s + 10.
The time the two cars traveled is equal but unknown, so let the time = t.
First car: speed = s + 10; time = t; distance = 120 miles
d = st
120 = (s + 10)t
(s + 10)t = 120 Equation 1
Second car: speed = s; time = t; 100 miles
d = st
100 = st
st = 100 Equation 2
Equations 1 and 2 form a system of 2 equations in 2 unknowns.
(s + 10)t = 120
st = 100
Distribute t in the first equation.
st + 10t = 120
From the second equation we know st = 100, so substitute 100 for st.
100 + 10t = 120
10t = 120
t = 2
The time traveled was 2 hours.
Equation 2:
st = 100
Substitute t with 2.
s * 2 = 100
s = 50
The speed of the second car was 50 mph.
The speed of the first car is s + 10.
s + 10 = 50 + 10 = 60
Answer: The speed of the first car is 60 mph
Answer:
(-5, -8)
Step-by-step explanation:
Answer:
C
Step-by-step explanation:
Let length of rectangle be "l"
Let width of rectangle be "w"
We know,
LENGTH is 2 MORE THAN WIDTH, we can write:
l = w + 2
Also, note the perimeter is the sum of all 4 sides of a rectangle, thus:
length + width + length + width
Now,
The perimeter is given as 72, so we can write:
l + l + w + w = 72
2l + 2w = 72
We have 2 equations that we need to solve and find the length (l).
The first equation is:
l = w + 2
Rearranging, we have:
w = l - 2
We put this into 2nd equation and find the value of l:
The length is 19 meters, the correct answer is C
Answer: 45
Step-by-step explanation:
300 * 0.15 = 45
