If a square has a length of 3x-y, what is its area?

9x² - 6xy + y²

Step-by-step explanation:

The square of the binomial can be written directly using the relationship ...

(a + b) ² = a² + 2ab + b²

where you have a=3x and b=-y.

area = (3x - y) ² = (3x) ² + 2 (3x) (-y) + (-y) ²

area = 9x² - 6xy + y²