Answer:
We know that the area of a square of side length L is given by:
A = L^2
Here, the total area of the white square is:
A = (3x + 1)^2
And the area of the shaded square is:
A' = (2x + 3)^2
a) If we remove the shaded area from the white area, the remaining area is just the difference between the two, then:
area = A - A' = (3x + 1)^2 - (2x + 3)^2
This is the expression we wanted.
b) Now we need to expand and simplify the expression:
area = (3x + 1)^2 - (2x + 3)^2
area = (3x)^2 + 2*(3x)*1 + 1^2 - (2x)^2 - 2*(2x)*3 - 3^2
area = 9x^2 + 6x + 1 - 4x^2 - 12x - 9
area = (9 - 4)*x^2 + (6 - 12)*x + 1 - 9
area = 5*x^2 - 6*x - 8
This is the simplified equation for the remaining area.