Answer:
He is 20 at oldest, or 
Step-by-step explanation:
The first step in finding a possible age is:
Subtract 10 from 51, and you get 41. Divide by 2, and you get about 20.5.
This means Joe is younger than or 20 years old.
Answer:
The answer to your question is 450 km
Step-by-step explanation:
Data
First stage Second stage
speed 1 = 40 km/h speed 2 = 65 km/h
time 1 = 8 h time 2 = 2 h
Process
1.- Write the formula to calculate the speed
speed = distance / time
-Solve for distance
distance = speed x time
2.- Calculate the distance of the first stage
distance 1 = 40 x 8
distance 1 = 320 km
3.- Calculate the distance of the second stage
distance 2 = 65 x 2
distance 2 = 130 km
4.- Calculate the total distance
Total distance = 320 + 130
= 450 km
Answer: 3.64, 10.00
Step by step:
1/x^-7
It would look more like 1
------
-7 (as an exponent)
x
So if u were to use a calculator, which you probably might need, you would take the radius, square it by 3, multiply by 4 and then divide by 3.