Hello!
When finding the perimeter of a rectangle, you have to consider the properties of a rectangle. A rectangle has two pairs of equal sides where one is the width, while the other one is the length.
Now looking back at your question, it says "... a rectangle that is x units wide" ⇒ you let the width = x ; this is the same with "y units long" ⇒ length = y. Perimeter can just be : P = 24.
Therefore,
The equation would be:
x + x + y + y = P.
2x + 2y = P.
(Sub in P = 24)
∴ 2x + 2y = 24. (This should be your answer.)
:) Good luck (Message me if you have any problem)
this is an example of linear equations is one variable
Answer:
the correct solution has been explained
Step-by-step explanation:
Jackson,s reasoning is incorrect because it should be 8 ones and not 8 tens that would give 64

Moreover, 
as 
whereas
= 8
clearly, both quantities are different
Answer:
x = 3 or -3
Step-by-step explanation:
So you have the equation x² - 9 = 0
Move the 9 to the other side: x² = 9
Then take the square root of both sides:
= ±
x = ±
= ±3
x = 3 or -3