The perimeter of rectangle abcd is 42 cm and the area is 80 cm2. which equation can be used to find the dimensions of the rectangle? (hint: set up a system of equations). xy + 2x + 2y = (42)(80) x^2 + 80x - 42 = 0 x^2 - 42x + 80 = 0 x^2 - 21x + 80 = 0