A - 2/3 = 3/5 how much is a?

1. what are the missing reasons in the proof 2. it's in the second picture and 3

Wich statement could be used to explain why the function h(x)= x^3 has an inverse relation that is also a function

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm