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
1. x = 20 , x² = 400 and x³ = 8000
2. x = 7 , x² = 49 and x³ = 343
Step-by-step explanation:
Given values are;
2000, 7, 400, 20, 4000, 200
We have to find x, x² and x³.
Part 1:
We will take cube root to find x.
![\sqrt[3]{x^3} =\sqrt[3]{8000}](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7Bx%5E3%7D%20%3D%5Csqrt%5B3%5D%7B8000%7D)
Now, we will take square;
Therefore;
x = 20 , x² = 400 and x³ = 8000
Part 2:
x² = 49 , x³ = 343
Taking square root on x²
Therefore;
x = 7 , x² = 49 and x³ = 343
Keywords: cube root, square root
Learn more about cube root at:
#LearnwithBrainly
1.)
10/15 ÷ 5
= 2/3
2.)
7/21 ÷ 7
= 1/3
Answer:
Step-by-step explanation:
