If y= 40 when x= 8, find x when y= -50

What is the difference between regular convex and concave polygons

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

On #16 : explain how factoring a trinomial, ax^2+ bx+ c, when a does not equal 1 different from factoring a trinomial when a = 1.