The answer is: 
The explanation is shown below:
1- You have the following expression given in the exercise:

2- When you multiply signs, you obtain:

3. Now, you must add like terms, as following:

4. Therefore, you have that the expression simplified is:

Answer:
x = 2, y = 3
Step-by-step explanation:
i) It is given that 5x - 3y =1
ii) It is also given that x = 2y - 4
iii) we can substitute the value of x from ii) in the equation in i) and we will get 5(2y - 4) - 3y = 1 ⇒ 10y - 20 -3y = 1 ⇒ 7y = 21 ∴ y = 3
iv) substituting the value of y obtained in ii) we get x = (2 × 3) - 4 = 6 - 4 = 2.
v) Therefore x = 2.
Use the Pythagorean Theorem to find the diagonal of the rectangle.
The diagonal of the rectangle is the diameter of the circle.
Diameter (d) = 2 · radius (r)
Circumference (C) = 2· π · r → π · d