Answer:
A = 9x² - 6x + 1 units²
Explanation:
since the sides of the square are congruent and the 4 angles are 90°, then
the figure is a square
the area (A) of a square is calculated as
A = s² ( s is the side length )
here s = 3x - 1 , then
A = (3x - 1)² = (3x - 1)(3x - 1)
each term in the second factor is multiplied by each term in the first factor
A = 3x(3x - 1) - 1(3x - 1) ← distribute parenthesis
= 9x² - 3x - 3x + 1 ← collect like terms
= 9x² - 6x + 1