Answer:
It will take 3.6 hours to wax a car if they work together.
Step-by-step explanation:
Calvin one hour work = 
Alvin one hour work = 
To find out how much they can do together per hour,
We have to add
and 
= 
=
--------------(1)
They can do
of the job per hour.
If "t" is the time taken to finish the job together, then one hour work
------------------------(2)
Now we have to find the value of "t" by setting the expression (1) and (2) equal.

It can solve by flipping the equation;

t = 3.6 hours
It will take 3.6 hours to wax a car if they work together.
Answer:
First, we know that the area of a rectangle of width W and length L is:
A = W*L
In the case of Roberto's plan, we can see that the length of the whole rectangle is:
L = 1.5ft + x + 1.5ft = 3 ft + x
And the width is:
W = 3ft + x + 3ft = 6ft + x
Then the area of the whole thing is:
A = (3ft + x)*(6ft + x)
This is what we wanted, a product of two polynomials that represents the area of Roberto's plot.
Now if we subtract the white square (is a square of sidelength x, then its area is A = x*x) we will get the area of the border;
The total area of Roberto's borders is:
Area of the border = (3ft + x)*(6ft + x) - x*x
= 3ft*6ft + 3ft*x + x*6ft + x^2 - x^2
= x*9ft + 18ft^2
Answer:
41% is equivalent to 41/100.