We let
x be the time it took John to get to his uncle's
y be the time it took John to get back from his Uncle's
So,
x + y = 12
And making use of the given velocities
20x = 30y
x = 3/2 y
Substituting to the first equation
3/2 y + y = 12
y = 4.8 h
Substituting to either of the equations
x = 7.2 h
Answer:

Step-by-step explanation:
We have been given the following equations;
f(x)=x^2−3x+2
g(x)=x^3−8
We are required to determine the composite function (f⋅g)(x). This simply means that we shall substitute the function g(x) in place of x in the function f(x);

Answer:
37.7 cm
Step-by-step explanation:
C = 2πr
2 · π · 6
≈ 37.7
I = / r where I = current and r = resistance
80 = k / 50 so
k = 400
so we have I = 400/r
when r = 40
I = 400/40 = 10 amps
Direct variation is of the form y = kx where k is a constant
So its A