Sarah wants to hang a mirror in her room. the mirror and frame must have an area of 15 square feet. the mirror is 3 feet wide and 4 feet long. which quadratic equation can be used to determine the thickness of the frame, x? square with an inner frame with height of 3ft on the left frame and width of 4ft on the top. arrow on the bottom frame with an x and an arrow on the right frame with an x. 3x2 + 14x − 2 = 0 4x2 + 14x − 3 = 0 x2 + 12x − 14 = 0 2x2 + 7x − 14 = 0