Answer:
B. 
Step-by-step explanation:
Let l represent length of rectangle and w represent width of rectangle.
We have been given four formulas for the perimeter of rectangle. We are asked to choose the formula that displays a common student error for finding the perimeter.
We know that perimeter of a polygon is sum of all sides of the polygon. We also know that rectangle is polygon having two sets of equal sides.
The perimeter, P, of rectangle will be sum of its all sides that is:

Combine like terms:

Factor out 2:

Upon looking at our given choices, we can see that formula represented by option B displays a common student error for finding the perimeter.
Answer:
25
Step-by-step explanation:
Compare the data and get the answer
Hey friend, hope I can assist you!
I will solve by elimination <3.
Multiply 3x - 7y = 2 by 2: 6x - 14y = 4
6x - 14y = 4
6x - 9y = 9
5y = 5
Now we have
6x - 14y = 4
5y = 5
Now we want to solve 5y = 5 for y
So simply divide both sides by 5.
5y/5 = 5/5
This gives us one or in other words, y = 1.
Now we want to plug y = 1 into 6x - 14y = 4
So 6x - 14 * 1 = 4
This gives us
6x - 14 = 4
Now add 14 to both sides.
6x - 14 + 14 = 4 + 14
6x = 18
Now divide both sides by 6
6x/6 = 18/6
This gives us 3 so x = 3
Therefore our solutions to this system of equations would be y = 1 and x = 3
Answer:
1.3888888888889 mps
Step-by-step explanation:
1 kph = 0.27777777777778 mps, so just multiply that by 5.