Since roots go down into the ground, the answers must be negative. That eliminates both 2 4/5 deep and 3.86. You could look at a number line if your unsure, but -3.54 is between 3 and 4, as is -3 2/5.
Area of Parallelogram = base x height
height = 4.5 cm
base = 4.5 cm x 2
height = 4.5 cm
base = 9 cm
9 cm x 4.5 cm = 40.50 cm^2
Solve for y like the top equation:
2y = -4ax + 11
2y/2 = -4ax/2 + 11/2
y = -2ax + 11/2