Can someone me out with some math?
the area of a rectangle is (81x^2 − 4y^2) square units. determine the dimensions of the rectangle by factoring the area expression completely. show your work.

81x^2 - 4y^2     Note this is the difference of 2 perfect squares

a^2 - b^2 = (a + b)(a - b)

so here we have a = 9x and b = 2y

and our factors are

(9x + 2y)(9x - 2y)

the dimensions are 9x + 2y and 9x - 2y