16x 2 25y 4 July 8, 2019 16 32 64 128 16x 2 25y 2 400 16x 2 25y 2 400 ellipse 16x 2 25y 2 4x 5y 16x 2 40xy 25y 2 16x 2 40xy 25y 2 factorise 16x 2 25y 2 400 0 16x 2 40xy 25y 2 1 Factor 16x 2 40xy 25y 2 The foci of 16x 2 25y 2 400 are
